AAEP Ask the Vet: Dentistry

Dentistry

A local dentist, choose to file the wolf teeth down to just below gum-level in preference to the standard extraction procedure. What are the chances of infection due to exposed pulp? Wolf teeth (in my short experience) does not seem to behave in as predictable a manner as the rest of the dental family! 

From the front to the back of the mouth are the incisors, canine teeth (if present), wolf teeth and a set of 3 deciduous premolars (first 3 cheek teeth), which are replaced by a set of 3 permanent premolars. Located in the deepest of the back of the mouth are the permanent molars (second three cheek teeth). All have some structural differences from each other but have basically the same functional makeup of types of cells. The clinical crown is the part of the tooth erupted from the gum and visible, the outer shell is a layer of cement, a layer of enamel (may be in exaggerated folds) and then internal cement. Within or central to the internal cement there are one or more additional rings of enamel and types of cement. And in the “middle” of the tooth there is dentin. The dentin, most central in the tooth, is formed by cells lining the blood pulp cavity. Those cells fill the cavity from the occlusal (chewing) surface towards the root of the tooth as the tooth wears, preventing pulp exposure and subsequent death of the cells located in and lining the pulp cavity. If the interior pulp cells of the tooth become infected, it is a pulp infection. If it travels up to the root, it becomes an apical root infection. There are various reactions that occur to limit infections and pulp stones and bone sclerosis are a couple that are common in horses with pulp exposure and root infections. Sometimes if the insult is relatively small, these stop the invasion of bacteria and cell death and goes no further, or the infection may spread into apical root infections and bone infections. In bone, an abcess forms (to wall off the “enemy” from the rest of the body) and may cause swelling and visible drainage of pus if there is an outlet such as into the sinus cavity, or an easy route to the outside of the body.

The healthy equine tooth is also attached to the bone socket (alveolar bone) by living ligament cells that adhere to the cement layer of the tooth and to layer of cells on the bone surface in the socket. These cells (forming Sharpey’s fibers) have a special role in herbivores that continue erupting teeth, because they are the cells that act to “crawl” the fully formed tooth out of the bone as it wears, and provide a continuous grinding surface for macerating fibrous foods. So the second place that a “tooth” infection can occur is around the inside of the socket, if the ligament holding the tooth becomes open to bacteria (such as occurs with geriatric horses when the tooth becomes short and is mechanically “wiggled”) or if a disease (such as pressure necrosis) causes the death of the ligament cells. Either way, the tooth loosens in the bone. Sometimes this is followed by the bone cortex (surface) inside the alveolar socket reacting to bacteria to form a cement-like attachment across the dead ligament to the tooth root.

The “wolf” tooth is morphologically a usually very small, vestigial (genetically disappearing) premolar tooth. Some wolf teeth are tiny and others may be large and long (2+ cm) and even have a molar like shape and may have a small blood pulp within. Some horses have one or no wolf teeth and a few have lower wolf teeth or displaced blind wolf teeth that do not erupt through the gum or sit in unexpected places like along the interdental space (bars) of the mouth. In horses older than 2 ½ years that have normally located wolf teeth (i.e. right near the second deciduous premolar tooth) the wolf tooth roots may already have been damaged by the acid bursa of the newly forming and perhaps already erupted permanent second pre-molar tooth. These may remain loose or may have sclerosis later and attach to the bone. I tend to be very cognizant of the location of the new nearby permanent tooth when removing wolf teeth that are near newly erupting, but not yet visible, permanent teeth. My goal then is to remove all the fragments of any size. If there was a question between leaving a fragment or protecting the new tooth. I opt to protect the tooth with certainty and make a note on the patient record to examine the area in a few months or next visit, removing any fragments remaining.

To finally answer the question in context, I believe the chance of an infection would depend on the size of the tooth, the age of the horse and whether a pulp is present in the tooth. I would guess that a chance of an infection of any significance would be very small.

My other thought to leave you with concerns the ligament condition over time. If the ligament allows the tooth fragment to migrate out, it may come in contact with soft tissue during riding much as the original spicule, or loosen and actually wiggle around in the gum against the bit. Since the whole reason to address wolf teeth at all is to insure a comfortable and safe bit experience for the horse and rider, purposefully leaving a fragment seems counter-intuitive to me. A small surgical procedure with an anesthetic block and the appropriate elevators and forceps is reliably very quick and simple, and without the root fragment present, the bone and gum heal amazingly fast; so… why not just remove it all? Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.


Can fretting from being stabled, and in muddy conditions, cause foaming and drooling?                 

Drooling is saliva that is either profuse release or a normal amount that is not being swallowed. 

If profuse and particularly slimy, it may be due to some type of irritation. 
If it is the type of salivation producing foaminess that is what you might see on the horse's mouth and lips when they chew on a bit continuously, thus is less indicative to me of direct mouth irritation. 
With your horse, my first examination would be to check inside the mouth making sure there is not overly sharp edges or problems with occlusion causing him to chew or irritate his cheeks. 
And secondly, to determine if  he is chewing on something - like wood or stall items - to irritate the  lips or mucosa. Thirdly, if there does not seem to be other obvious reasons why he would be drooling so much, I may want to consider ulcers as a possibility.  
With a stalled horse that is fretting regularly, stomach ulcers can be present. 
One theory associated with "ulcer" behavior in horses is increased pain from the lesions occurs as acid is released when eating a grain meal or when fretting. Ptyalism (constant grinding of teeth) is a reaction associated with ulcers in young horses. Chewing in general causes a saliva release in all horses, and calcium containing saliva actually has a buffering effect in the stomach. 
The surest way to diagnose ulcers is with a thorough endoscopic examination, which will include the stomach and upper dueodenum in the horse. 
If diagnosed with ulcers, the problem will usually respond well to term of 4-6 weeks of appropriate oral medication with omeprazole or ranitidine coupled with management changes such as more turnout and regular access throughout the day to grazing or access to forage. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.
  

I have a Quarter horse mare, approximatley 20 to 25-years-old. She is pasture kept with another Quarter horse 24/7. She was last dewormed in November. It has been a harsh cold winter, but she kept her weight really well as she and her buddy had shelter and blankets. They share a trough, which I fill with 8-10 flakes of hay for them. My horse is boss, so I know she is not being chased from the food. I also give her half a 3qt scoop of sweet feed in the morning and again in the evening. In January, I noticed she began quidding and her weight began slowly dropping, so I had her teeth done. Since then, she has been eating better, though I believe, with smaller mouthfuls, and a little less gusto than at the start of winter. She does not look too thin at first appearance, but she has a thick winter coat, and her weight has decreased. I can easily feel her ribs, which has me worried. Am I feeding enough? Should I increase hay, grain, or both? She did really well with this feeding schedule throughout the winter, but am trying to figure out what has changed.


With reference to an older horse that has had some signs of dental insufficiency and weight loss, l will address some dental information first and then some suggestions for feeding the older equine.  This is a general discussion, and I would suggest you consult for your mare and her health specifically with your trusted veterinarian.

Quidding is rolling the hay rather than cutting it when chewing and usually spitting it out uneaten. With adequate grinding ability the horse will move hay into the front cheek teeth and grind and then move it from cheek to tongue and onto the next teeth a bit farther back and repeat…each grind should result in shorter and shorter pieces of hay until it is macerated into very tiny particles at the back teeth and is in a homogenous bolus and swallowed. Horses that can move the jaw with enough motion but that cannot make contact to cut the hay with their teeth form a twisted “rope” of hay. There is other dysfunctional chewing that may form pads or lumps of hay and horses may actually be swallowing these even though they are not well chewed. A good way to get an idea of chewing efficiency is to inspect manure for hay and whole grains. Normally there is not much, if any, recognizable hay and no whole grains visible.

Diarrhea can be caused by other illnesses and by sand, or by diet changes made too quickly… but I see some cases in older horses where it is actually caused by undigested food molecules in the large intestine drawing water in and causing intermittent diarrhea.  Large particles of food are not conducive to attack by the flora and it does not provide for normal proliferation of flora. Once the particle size is corrected the micro-flora population usually returns quickly in a few days, and the diarrhea abates. This can be as simple as adding hay pellets or senior food to their diet. The population of intestinal micro flora forms a significant source of protein for the horse.

Equine teeth are formed and erupt into the mouth from before birth into the fourth year (canines a bit later). Cheek teeth continue to lengthen in the maxilla and mandible until around eight years old and from that point on they simply erupt as they are worn off, until only a short root section of tooth is remaining. Sometimes these may fall out or they can partially loosen and roll into the cheek or break into pieces.

In my experience horses into the mid to late twenties on average, begin to lose their ability to erupt any more tooth length. It is never all the teeth at once so the problem with chewing may be compounded by uneven attrition and wear, waves, steps, slants  and the result is chewing  just slowly becomes less efficient, and the jaw muscles will reflect this with visible atrophy. Shortening and leveling the incisors (front teeth) regularly is important as well, particularly in older horses, since they may have longer incisors and shorter (worn) cheek teeth.   

Even though your mare is now chewing well enough to no longer quid, it may be that her teeth are worn so that she will need pelleted food to provide her with enough hay calories. If you feel she may be uncomfortable, a speculum exam to look for fractured or loosened teeth due to wear is appropriate.

There are many good ways to design a senior diet. The goal is a diet that; meets the basics for nutrition and leaves the horse with something to “graze” food or grass throughout most of the day and night, provides food of a “digestable” particle size, and is a diet that works for your management scheme. Each situation has a lot of factors that may play into what will work best, such as: 

* Pasture companions

* Hay availability

* Where, in the range of tooth attrition your older horse actually is, can they eat some grass but not hay?

* How easy of a keeper are they?  

There is also an array of major food manufacturer websites that have articles about special nutrition, such as low glycemic index foods and higher fat foods, feed calculators online, and the larger companies employ highly educated nutritionists and veterinarians that may provide information and support for owners and veterinarians for consultation about their products.  

Additionally, some health issues can cause loss of muscle mass -PPID (Equine Cushing’s) and abnormal fat distribution –EMS (Equine Metabolic Syndrome). Advanced PPID can be the cause of unnaturally curly or long hair coats and contribute to Insulin dis-regulation these statistically become more prevalent in the older population of horses. There are many foods available in pelleted “senior” form for special health issues so if you have a horse with health issues work with your vet to find the right one for your older horse.

  1. Always make changes slowly over 10-14 days, this allows time for the micro-flora to adapt to new food.
  2. A kitchen food scale is important, every food has a different weight per scoop, and feeding directions is likely in pounds.
  3. Calculate adequate calorie intake to maintain weight. These calories come as… concentrates, forage, pasture and ration balancers. If a horse cannot chew the needed amount of forage then a senior food may be appropriate.  Senior food is usually a “complete” food. This indicates that there is both concentrate and hay both and the food is formulated with sufficient fiber to provide a minimum of “forage” even if no additional hay is fed.  The recommended feeding rate is much larger than the regular concentrate food.  This makes sense since it contains “hay” as well as the concentrate.  Senior foods have amounts for feeding alone or with a minimum recommended amount of hay, so read the bag for each food.

They also have a minimum amount by weight listed that must be fed to “balance” the diet, Usually it is about 6 lbs /1000 lb BW and would require a lot of hay additionally to support a 1000 lb horse…so this means a scoop of senior will not provide the necessary vitamins and amino acids for a balanced diet unless you are feeding a mini!

  1. Forage- all horses need fiber in adequate amounts, usually 1.5-2.0 % of BW, with 1.5% as a minimum for healthy gut function, which includes gut flora.  For example, a 1000 lb horse needs around 15 pounds a day (minimum) of some type of hay; flakes, chopped forage, or pelleted forage.

How do you decide which form? The one they can chew well or pellets! If they are sorting stems out of hay, quidding, or just leaving hay, but eating easier to chew foods, then they probably need pelleted hay and /or a “complete” food. If still eating some hay, but not keeping weight they may be able to eat a moderate amount of senior food and continue to eat hay.  

Hay cubes are not equal to pellets, when soaked they still have a large percentage of 1-2” stems that needs to be chewed in order to be utilized. Remember, wet food to a soft consistency if your horse may gulp it.

There are two big advantages to adding Senior or hay pellets into the diet even if your horse can still chew some hay.

1-      A risk for colic is likely greatly reduced by mixing in some small particle foods.

2-      The small particles will allow a normal population of flora to proliferate. This increases the protein available from hay and fibers for digestion.

For example: 1000 lb horse …generally was an easy keeper until his teeth became worn.

He use to eat 3 lbs of concentrate food, 15 lbs of grass hay and one small pad of alfalfa per day split into 2 meals and had a paddock of short grass to graze between meals (20 lbs of forage total).

Now he has trouble with hay stems and leaves them, he has a few intermittent bouts of loose manure now and then (his veterinarian finds him healthy) but he has a lot of visible hay and oats from the concentrate in his manure…

 Now he will eat…

6 lbs of a “Complete” and “Balanced” Senior food, 10 lbs of timothy pellets, and 3 lbs of Alfalfa pellets and grass (since he can still nip and chew some soft fresh grass at pasture).

I figure about half the weight of the senior complete food as a portion of the daily “hay” ration, and the wetted hay pellets will replace his hay that he can no longer chew. He goes back to being an easy keeper.

Or… for a very senior horse that is a hard keeper and cannot chew even grass anymore…

15 lbs of Senior (based on the ideal body weight and the feeding amounts given by the manufacturer).  Always divide meals so less than 5 lbs per meal is fed for a 1000 lb horse. The more meals you can manage thru the day the better for the horse and the more you will stretch your food dollars, because they will likely get more energy out of the same food if eaten slowly in smaller meals. Large meals tends to cause the stomach to empty prematurely.

  1. horse specific mineral balancer and free choice salt, is recommended by most all feed companies in addition to their foods.  Since balanced foods contain the minimum of daily required minerals for all horses, it is adequate only if the animal; isn’t sweating a lot, isn’t ridden a lot, isn’t stressed...etc.  Extra needed minerals, is made up by what you provide beyond the balanced food. I personally use loose minerals and loose salt in separate feeder tubs in my run in barns, loose salt is especially nice for older horses since their incisors may not be as comfortable as they used to be so, they may not get enough on hot days just licking a block. Red salt/ trace mineral blocks are just that- mostly salt and not equal to providing a “real” mineral balancer.

For me free choice usually works best, because most animals are very good self-regulators when it comes to salt and minerals, but always limit it until you see how much your horse will eat.

If necessary, dole out a few tablespoons or ¼ cup a day for a full sized horse until the novelty has worn off and they are satisfied.

I personally stay away from adding electrolytes or minerals right into food. This is the equivalent of “force feeding”; most animals will eat the food regardless, and it is rare that a healthy horse not in extreme work needs electrolytes daily. Electrolytes can dehydrate your horse if overfed.

Senior horse notes…

  • Choking is a possibility for any horse not chewing food well. If you aren’t sure that your senior horse will be able to chew dry pellets with the tooth he has remaining or if any horse tends to eat big mouthfuls too fast, then covering the pellets with water at feeding time to make a wet oatmeal is a good idea. “Soupier” is usually hard for them to eat.
  • I find that timothy hay pellets are not nearly as “good” to most horses than senior food or alfalfa pellets…so you can use them separately in a pan (wet if need be) for a pasture food that will be eaten slowly. For example…I feed regular hay to my younger horse and a pan of wet timothy pellets to my geriatric (he is 31) in the same pasture and it works well. My younger horse prefers hay and my older guy can’t chew hay. I separate them at “feeding” time twice a day, so my senior can eat his 4 lbs of senior food  and 1 lb of alfalfa pellets slowly during those meals and not get robbed.
  • Management usually consists of figuring out how to leave the senior with a buddy nearby…for grooming over a fence or sleeping, but allowing them plenty of separate time with their food so they can eat slowly.
  • Try not to leave long periods without chewable food to “graze” on.
  • Be cognizant if wetting food that it can sour quickly and if the horse is not eating it –then it may be soured. This is especially true in hot weather. 
  • Senior horses usually require extra protein so most senior foods are a bit higher in protein 12-14%.
  • Look up and learn to judge your horse’s condition by using an Equine body condition scoring system, and use a weight tape to track trends. Try to have your horse gain less than 1/2 pound per day if gaining weight back.
  • Don’t discount the possibility of PPID in older horses, it is statistically very prevalent in horses by their mid-twenties and treatment to control the symptoms can greatly increase your horse’s longevity and quality of life. Talk to your veterinarian sooner rather than later, if you suspect your horse may be affected by PPID. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

 

My horse has a severe parrot mouth. Floating to remove the hooks/ramps is done twice a year but the incisors have been left untouched for more than two years. The top incisors don’t make contact with anything and the bottom incisors make contact with the palate. How do you know when it is time to have their incisors reduced in length? There aren’t any visible sores on the palate but weight loss and shaking the head have become an issue. (View Answer)

It would be difficult for me to give you a specific opinion, without first doing an exam to determine the ability for your horse to touch the cheek teeth for grinding, and the extent of the interference of the incisors. Working on the teeth myself would aloe me to determine how much I would be comfortable removing if shortening is necessary.  So please consider this a general discussion of the obstacles I may consider and a few of the techniques that I might use for a case of severe maxillary prognathism  (parrot mouthed) horse, not necessarily my recommendations for your horse.   Formulating and monitoring a plan for their care can be challenging. The amount of work and accuracy of the work needed lends itself to using electric grinding burrs rather than hand tools for me, but that is a personal preference and although most dental focused practitioners have these tools available incisor work can be done without them.  There are some, rarer yet, cases that cannot be kept functional or comfortable by dental maintenance and then a surgical removal of some or all of the incisors may be a consideration. This is only a decision I would make in severe cases where shortening has failed to be successful and the horse is unable to be made comfortable to eat.

There are also other health issues that may cause what you describe, so I would be remiss if I did not encourage you to have a thorough examination done first with your local veterinarian to rule out other health issues.

Generally starting early in life for this type of malocclusion (as soon as the teeth are beginning to over grow) and likely planning on maximum shortening work 2-4 times yearly on the incisors, while attempting to preserve much of the normal length of the cheek teeth through very conservative work will allow for the best clearance of the lower teeth from the palate and the upper and lower incisors from each other.  Palate contact forms a hardened callous on the palate directly behind the upper incisors where the teeth are pressing against it. Sometimes the interference to normal chewing occurs by the overlapping contact of the incisor teeth themselves with each other. This can be recognized by checking grinding ability carefully through grasping the upper and lower face and moving a relaxed jaw in the chewing motion. Either way, shortening the incisors as much as feasible is usually helpful. Even if the overlap is partial with a bit of incisor occlusion at the corners (03’s) the incisor arcades still need to be level from left to right across the entire set of teeth so that both the  side to side and slight front to back “orbital” motion during chewing is not impinged. If the incisors are longer than normal and occluding at all then they are likely affecting the grind of the cheek teeth.

When starting on an older horse where the incisor length has gotten ahead of a shortening plan I do try to accomplish as much shortening as I consider feasible each visit to make headway, and I would want to see the horse a few times yearly so that there is  3-4 months between visits for the pulp cavity to fill with tertiary dentin for protection, but not so much time that headway in progressively shortening the incisors is lost. I would caution that when I am attempting to do a maximum amount of work on any teeth I almost never actually go by a set measurement of length to remove, because it can be very variable among different teeth and different breeds and ages of horses. Making an assumption that you can remove a set amount may give unexpected results if teeth are shortened quickly assuming you have a “safe” amount of tooth to remove.  I keep an idea in mind of how much my general goal is, but my guide is to watch each tooth carefully for subtle color changes during shortening and to work very slowly. This gives me the best opportunity to do a good amount of work for the horse at each visit but to know when I want to stop shortening and put off additional work for another visit.

 I have seen quite a few horses over the years with incisor trauma from kicks and trailer bumps, fights and collisions with stationary objects, causing a fracture with a severely opened incisor pulp and/or deeply fragmented incisors and a large percentage of these create a pulp stone that plugs the pulp cavity and prevents a root infection on their own.  Cheek teeth fractures tend to not be as forgiving; the roots are multiple and branched and infections from fractures are common.  So I am even more likely to stop work earlier to protect the cheek teeth from accidentally touching a pulp tip.  For teeth that are preventing proper chewing I try to be as aggressive as possible to bring them back to proper occlusion but stop to protect pulp if in doubt. The age of the horse also contributes to the decision of how much shortening I am comfortable to do, young incisor teeth that still have the shelly cusps can usually be shortened quite a bit while working on the edges around the “cup” but as soon as the initial edge is removed, young teeth may have a large pulp closer to the surface than older teeth.

Since the pulp of the teeth may dictate when you have to stop shortening, or you may know when starting work that you will not be doing as much shortening as you wish in a single visit, I work mostly on the longest teeth first to bring them into level and then continue shortening equally so the arcade is as level as possible when I stop.  Level and free lateral movement of the mandible is dictated to a great extent by the path of the incisors which allows normal function for the occlusion or grinding ability of normal balanced cheek teeth and provides for normal apposition of the surfaces of the TMJ. My goal is primarily to relieve incisor trauma to the palate and interference with the other teeth, while keeping in mind that a pulp cavity can be opened from the side of a tooth as well as from the bottom of the tooth.

With respect to the joint and dental imbalances and restrictions… many important facial and proprioceptive nerves, both motor and sensory types of nerves, pass near or within the fascia associated with the TMJ and protecting or improving proper grinding ability allows the least abnormality to the joint function and improves many clinical signs that may be associated with joint nerve irritation or joint soreness directly. While I would agree that perfecting teeth cannot fix all maladies… there are a surprising number of problems that may be associated with imbalances of the teeth,  such as;  head tossing, bucket flinging at meals, disagreeable attitudes about bitting or having ears and face handled, sensitivity at the poll with increased resistance to haltering and tying, all the way up to problems resisting collection and/or flexion in work, resulting in heaviness riding,  stopping at jumps, stiffness in turns…etc… etc, and of course obvious problems eating such a quidding hay, dropping grain and inappetance if uncomfortable to the extreme.  The solution for many horses is to free the restrictions to normal jaw motion while correcting the angles and overall ease of contact of the cheek arcades. This does not necessarily mean the teeth are “smooth” to the extreme.  I am a proponent of conservative smoothing when necessary, but occlusal surface interface angle and quality grind that does not require abnormal lateral motion is by far more important in my opinion.  Over aggressive smoothing with a significant amount of enamel removal may cause accelerated wear beyond the capacity of the horse to erupt replacement crown length.  If cheek teeth are shortened by accelerated wear to the point of not supporting the grinding cycle then TMJ discomfort and the horse’s purposeful disuse of the chewing muscles will likely follow in my experience. Atrophy of those muscle groups can be seen easily in many of these cases.

 With all that said… the balance for the cheek teeth, as well as the height of the overall arcades and angle of the surfaces that occlude must be kept very close to as normal as possible,  because a severe “uphill”  lower  arcade or significantly “long” upper front cheek teeth may “help” by holding the incisors apart; but abnormal heights of some of the teeth in the cheek arcades may also cause uneven wear of the back teeth due to abnormal pressure and problems chewing but also improper opposition of the TMJ’s. This then becomes a factor in my opinion of a host of other secondary problems such as: irritability with the face or ears being handled, poor bit acceptance and contact, poor collection or flexion, habits during eating such as bucket flinging or head tossing, as well as, long term abnormal inter-articular cartilage wear, abnormal forces on the meniscus within the joint and accelerated arthritic changes of the joint. 

So… I would suggest seeking a physical exam, a dental exam and start on needed corrections.  In the short term you may want to consider feeding as you would an old horse with dental problems chewing, so wet hay pellets (not cubes), the consistency of oatmeal to replace some of the hay (by dry weight). And consider a senior or senior low starch, complete food, as appropriate.   If your horse is older with a possibility of PPID, or you know your horse has special health issues it is particularly important that you seek veterinary advice for a diet change.  Using the feeding instructions for the food you choose is important as well. Researching diets for horse with problems grinding food may give you some insight for diet and management. Just a change to hay pellets may drastically increase absorbable calories if there was a previous problem grinding hay. Remember to make any changes to diet slowly over 7-10 days and make increases of absorbable calories slowly as well. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

 

AAEP Ask the Vet: Emergency Care

1.  About 5 weeks ago, my pony had a small lump show up on the left side of his face. I left it over night without too much worry. When I returned the next morning, it was completely swollen and swelling had moved across the bridge of his nose (about where a noseband goes) to the right side. His right nostril was also draining much of a green discharge. We contacted the veterinarian who told us that it looked like a tooth concern and put him on bute and antibiotics. They returned a few days later to take x-rays, that showed what looked almost like a small marble either in a tooth in the back (left side, where it originally started) or behind the tooth. The veterinarian still does not really know what is causing the problems of  the sinuses, such as a tooth, snake bite, etc. All of this began in February and since then, they have threw antibiotics at him and some kind of sand pill to loosen the object(s). The swelling is now gone but the nostril is still draining a bit. Also, where the swelling was located on the left side of his face, the hair came off and a bubble appeared. It later popped and green discharge as well as blood came out. The veterinarian still has no real idea as to what this was. Do you have any ideas?

What you are describing sounds like a foreign body either in the sinus or under the skin. Bullets or BB injuries can appear this way and may penetrate the sinus and result in an infection. Careful exploration of the "bubble" on the pony's face may reveal a hole into the sinus or the foreign body located under the skin. Repeat radiographs of the skull may give a better picture of the "marble" seen on the first radiographs. If the object is a piece of the pony's tooth, it will not have moved much if at all. If the marble is a piece of another animal's tooth or a bullet fragment, it may have moved significantly. Rarely, the object seen on the radiograph can be a worm or fly larvae that has calcified.

If exploration of the skin bubble and radiographs do not indicate the problem, the sinus may need to be explored. The sinus can be explored endoscopically either by passing the scope up the nostril and examining the sinus opening or drilling a hole into the sinus and placing the scope into the sinus through the hole. If necessary, the sinus can be opened by creating a bone flap over the area. Depending on the temperament of the horse, this can be done with standing sedation. Dr. Manuel Himenes, Kailua, HI

2. I have a 12-year-old Quarter horse gelding that I have had since he was 2. At 4-years-old, I began training him for barrels, which he did quite well. He was very flexible and had excellent turns. However,  around the age of 7 and 8 his performance declined. He began to turn stiff and very moody when ridden. The last couple years he began to cringe when I cinched him, walking stiff and wild eyed and waiting to set back. This occurred even after a month layoff. The things we have done from day one when the problems began consisted of, hocks injects, changed pads, girths and saddles. We contacted a chiropractor in which they adjusted the hips. The chiropractor even said his neck was out along with his sternum, which he continued to adjust monthly. The muscles on his underline will get hard and you can press and he begins to move. This never gets better even after layoff or an examination from the veterinarian or chiropractor. We are at our wits in. When I ride him he feels off and I can't pinpoint where. Please help he is a sweet horse and is too nice to retire. I would really like to find the problem.

Sorry to hear about your horse's problem. He sounds like a nice horse and you and he have been together for a decade. These type of longstanding problems are a challenge to diagnose.The clinical signs that you have described can be caused by many disorders. Muscle metabolism disorders, genetic disease, occult lameness and gastric ulcers are just some of the problems that come to mind.

Does he have any of the Impressive bloodline? If he does, has he or his parents been tested for the hyper kalemic periodic paralysis (HYPP) gene? If he is negative for HYPP I would begin by doing a basic blood panel paying close attention to muscle enzymes creatinine kinase (CK), aspartate aminotransferase (AST) and electrolytes. If these enzymes and electrolytes are within the normal range, the blood chemistries should be repeated after exercise. If they are still within the normal range, it is unlikely that the horse is tying up. If the enzymes are significantly elevated, he may be having episodes of exertional rhabdomyolisis or "tying-up" syndrome. Rhabdomyolysis can be genetic or diet related. Deficiencies of vitamin E and/or selenium can cause this syndrome and can be diagnosed with a blood test. If your horse has genetic predisposition to tying up the diagnosis can only be made by muscle biopsy. Treatment of these conditions is done through dietary therapy.

If the muscle enzyme tests are negative, a careful lameness exam would be a good next step. This exam should involve watching the horse go in hand, on the lunge line in both directions and possibly under saddle. A hoof tester exam should be done on all four hooves along with fetlock, carpal (knee) and hock flexions. If any lameness is noted diagnostic analgesia, nerve blocks, can be done. If the lameness can be localized with the nerve blocks, radiographs and /or ultrasound exams are warranted. If no lameness is noted on exam nerve block of both front feet may be done to conclusively rule out laminitis. If theses tests do not localize a painful area, referral for advanced diagnostic techniques may be needed.

Dr Bertone's work a few years ago showed that horses with gastric ulcers can have a multitude of clinical signs. After ruling out other sources of pain ulcers should be considered. I prefer to examine the stomach with an endoscope. However, there are fecal occult blood tests that have been shown to be useful in diagnosing gastric ulcers. 

Rib fractures, vertebral fractures, arthritis of the vertebral facets and sternal fractures are also disorders that could cause the signs you are seeing. Contact your veterinarian and discuss a diagnostic plan that you are comfortable with. Once you have a diagnosis, you can then proceed with treatment and hopefully get you and your horse working together again. Dr. Manuel Himenes, Kailua, HI

3. I own a 6-year-old Rocky Mountain horse. He recently received his rabies and also the 3-way combo with West Nile. We elected to do his pneumo shot a month later. A day after his vaccines, he was acting normally in his pasture, eating , drinking, etc., but when I went out for a short ride, we immediately turned around because he was just acting 'off'. I checked his temperature and to my surprise it was 103.8! I treated him with banamine in which his temperature decreased to 100.2 within a 2-hour period and he subsequently felt better. My question is: what should I do for future vaccines? This is the first time we gave the combination shot. In years past, he received individual injections, all in the same day without noticeable reaction. However, nothing in the past has prompted me to take his temperature. As an aside, he is a horse that does seem to be with allergies, at least to bug bites. I recently started him on The Natural Vet Bug Check, which contains probiotics, which he does seem much better. Do probiotics help with allergies, more than just the response to bugs?

Your horse appears to have had a reaction to the adjuvant combination vaccine. Adjuvant are the part of the vaccine that enhances the immune response. Since your horse did not react to the individual vaccines, I would suggest that in the future the horse be vaccinated using the single disease vaccines and not the combination. You may also need to spread the vaccinations out over a few days. If these options are not feasible, I would try a banamine dose on the day of vaccination. Separating the vaccines would be preferable.

Probiotics are a complicated topic. The intestinal has a lot of immune system tissue and some believe that allergies may be related to improper intestinal bacterial balance. This idea is controversial but probioitics will not do any harm. Dr. Manuel Himenes, Kailua, HI

4. I own a 19-year-old Thoroughbred that recently has come down with cellulitis. My veterinarian is treating him with Penicillin. He started him today on gentomycin My questions are: what does the gentomycin do and I heard this could last for three (3) weeks? Any additional information would be appreciated.

Gentomycin is an antibiotic that is synergistic with penicillin. That means that combining penicillin and gentomycin is more effective than either one alone. Cellulitis can be a prolonged treatment especially if the swelling persists. If your horse can be walked, moving helps the circulation and reduces the swelling. Dr. Manuel Himenes, Kailua, HI

AAEP Ask the Vet: Dentistry

Dentistry
  1.  A local dentist, trained in the U.S., choose to file the wolf teeth down to just below gum-level in preference to the standard extraction procedure. What are the chances of infection due to exposed pulp? Wolf teeth (in my short experience) does not seem to behave in as predictable a manner as the rest of the dental family!

From the front to the back of the mouth are the incisors, canine teeth (if present), wolf teeth and a set of 3 deciduous premolars (first 3 cheek teeth), which are replaced by a set of 3 permanent premolars. Located in the deepest of the back of the mouth are the permanent molars (second three cheek teeth). All have some structural differences from each other but have basically the same functional makeup of types of cells. The clinical crown is the part of the tooth erupted from the gum and visible, the outer shell is a layer of cement, a layer of enamel (may be in exaggerated folds) and then internal cement. Within or central to the internal cement there are one or more additional rings of enamel and types of cement. And in the “middle” of the tooth there is dentin. The dentin, most central in the tooth, is formed by cells lining the blood pulp cavity. Those cells fill the cavity from the occlusal (chewing) surface towards the root of the tooth as the tooth wears, preventing pulp exposure and subsequent death of the cells located in and lining the pulp cavity. If the interior pulp cells of the tooth become infected, it is a pulp infection. If it travels up to the root, it becomes an apical root infection. There are various reactions that occur to limit infections and pulp stones and bone sclerosis are a couple that are common in horses with pulp exposure and root infections. Sometimes if the insult is relatively small, these stop the invasion of bacteria and cell death and goes no further, or the infection may spread into apical root infections and bone infections. In bone, an abcess forms (to wall off the “enemy” from the rest of the body) and may cause swelling and visible drainage of pus if there is an outlet such as into the sinus cavity, or an easy route to the outside of the body.

The healthy equine tooth is also attached to the bone socket (alveolar bone) by living ligament cells that adhere to the cement layer of the tooth and to layer of cells on the bone surface in the socket. These cells (forming Sharpey’s fibers) have a special role in herbivores that continue erupting teeth, because they are the cells that act to “crawl” the fully formed tooth out of the bone as it wears, and provide a continuous grinding surface for macerating fibrous foods. So the second place that a “tooth” infection can occur is around the inside of the socket, if the ligament holding the tooth becomes open to bacteria (such as occurs with geriatric horses when the tooth becomes short and is mechanically “wiggled”) or if a disease (such as pressure necrosis) causes the death of the ligament cells. Either way, the tooth loosens in the bone. Sometimes this is followed by the bone cortex (surface) inside the alveolar socket reacting to bacteria to form a cement-like attachment across the dead ligament to the tooth root.

The “wolf” tooth is morphologically a usually very small, vestigial (genetically disappearing) premolar tooth. Some wolf teeth are tiny and others may be large and long (2+ cm) and even have a molar like shape and may have a small blood pulp within. Some horses have one or no wolf teeth and a few have lower wolf teeth or displaced blind wolf teeth that do not erupt through the gum or sit in unexpected places like along the interdental space (bars) of the mouth. In horses older than 2 ½ years that have normally located wolf teeth (i.e. right near the second deciduous premolar tooth) the wolf tooth roots may already have been damaged by the acid bursa of the newly forming and perhaps already erupted permanent second pre-molar tooth. These may remain loose or may have sclerosis later and attach to the bone. I tend to be very cognizant of the location of the new nearby permanent tooth when removing wolf teeth that are near newly erupting, but not yet visible, permanent teeth. My goal then is to remove all the fragments of any size. If there was a question between leaving a fragment or protecting the new tooth. I opt to protect the tooth with certainty and make a note on the patient record to examine the area in a few months or next visit, removing any fragments remaining.

To finally answer the question in context, I believe the chance of an infection would depend on the size of the tooth, the age of the horse and whether a pulp is present in the tooth. I would guess that a chance of an infection of any significance would be very small.

My other thought to leave you with concerns the ligament condition over time. If the ligament allows the tooth fragment to migrate out, it may come in contact with soft tissue during riding much as the original spicule, or loosen and actually wiggle around in the gum against the bit. Since the whole reason to address wolf teeth at all is to insure a comfortable and safe bit experience for the horse and rider, purposefully leaving a fragment seems counter-intuitive to me. A small surgical procedure with an anesthetic block and the appropriate elevators and forceps is reliably very quick and simple, and without the root fragment present, the bone and gum heal amazingly fast; so… why not just remove it all? Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

 2. Can fretting from being stabled, and in muddy conditions, cause foaming and drooling?

Drooling is saliva that is either profuse release or a normal amount that is not being swallowed. 

If profuse and particularly slimy, it may be due to some type of irritation. 

If it is the type of salivation producing foaminess that is what you might see on the horse's mouth and lips when they chew on a bit continuously, thus is less indicative to me of direct mouth irritation. 

With your horse, my first examination would be to check inside the mouth making sure there is not overly sharp edges or problems with occlusion causing him to chew or irritate his cheeks. 

And secondly, to determine if  he is chewing on something - like wood or stall items - to irritate the  lips or mucosa. Thirdly, if there does not seem to be other obvious reasons why he would be drooling so much, I may want to consider ulcers as a possibility.  

With a stalled horse that is fretting regularly, stomach ulcers can be present. 

One theory associated with "ulcer" behavior in horses is increased pain from the lesions occurs as acid is released when eating a grain meal or when fretting. Ptyalism (constant grinding of teeth) is a reaction associated with ulcers in young horses. Chewing in general causes a saliva release in all horses, and calcium containing saliva actually has a buffering effect in the stomach. 

The surest way to diagnose ulcers is with a thorough endoscopic examination, which will include the stomach and upper dueodenum in the horse. 

If diagnosed with ulcers, the problem will usually respond well to term of 4-6 weeks of appropriate oral medication with omeprazole or ranitidine coupled with management changes such as more turnout and regular access throughout the day to grazing or access to forage. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

3.  I have a Quarter horse mare, approximatley 20 to 25-years-old. She is pasture kept with another Quarter horse 24/7. She was last dewormed in November. It has been a harsh cold winter, but she kept her weight really well as she and her buddy had shelter and blankets. They share a trough, which I fill with 8-10 flakes of hay for them. My horse is boss, so I know she is not being chased from the food. I also give her half a 3qt scoop of sweet feed in the morning and again in the evening. In January, I noticed she began quidding and her weight began slowly dropping, so I had her teeth done. Since then, she has been eating better, though I believe, with smaller mouthfuls, and a little less gusto than at the start of winter. She does not look too thin at first appearance, but she has a thick winter coat, and her weight has decreased. I can easily feel her ribs, which has me worried. Am I feeding enough? Should I increase hay, grain, or both? She did really well with this feeding schedule throughout the winter, but am trying to figure out what has changed.

With reference to an older horse that has had some signs of dental insufficiency and weight loss, l will address some dental information first and then some suggestions for feeding the older equine.  This is a general discussion, and I would suggest you consult for your mare and her health specifically with your trusted veterinarian.

Quidding is rolling the hay rather than cutting it when chewing and usually spitting it out uneaten. With adequate grinding ability the horse will move hay into the front cheek teeth and grind and then move it from cheek to tongue and onto the next teeth a bit farther back and repeat…each grind should result in shorter and shorter pieces of hay until it is macerated into very tiny particles at the back teeth and is in a homogenous bolus and swallowed. Horses that can move the jaw with enough motion but that cannot make contact to cut the hay with their teeth form a twisted “rope” of hay. There is other dysfunctional chewing that may form pads or lumps of hay and horses may actually be swallowing these even though they are not well chewed. A good way to get an idea of chewing efficiency is to inspect manure for hay and whole grains. Normally there is not much, if any, recognizable hay and no whole grains visible.

Diarrhea can be caused by other illnesses and by sand, or by diet changes made too quickly… but I see some cases in older horses where it is actually caused by undigested food molecules in the large intestine drawing water in and causing intermittent diarrhea.  Large particles of food are not conducive to attack by the flora and it does not provide for normal proliferation of flora. Once the particle size is corrected the micro-flora population usually returns quickly in a few days, and the diarrhea abates. This can be as simple as adding hay pellets or senior food to their diet. The population of intestinal micro flora forms a significant source of protein for the horse.

Equine teeth are formed and erupt into the mouth from before birth into the fourth year (canines a bit later). Cheek teeth continue to lengthen in the maxilla and mandible until around eight years old and from that point on they simply erupt as they are worn off, until only a short root section of tooth is remaining. Sometimes these may fall out or they can partially loosen and roll into the cheek or break into pieces.

In my experience horses into the mid to late twenties on average, begin to lose their ability to erupt any more tooth length. It is never all the teeth at once so the problem with chewing may be compounded by uneven attrition and wear, waves, steps, slants  and the result is chewing  just slowly becomes less efficient, and the jaw muscles will reflect this with visible atrophy. Shortening and leveling the incisors (front teeth) regularly is important as well, particularly in older horses, since they may have longer incisors and shorter (worn) cheek teeth.   

Even though your mare is now chewing well enough to no longer quid, it may be that her teeth are worn so that she will need pelleted food to provide her with enough hay calories. If you feel she may be uncomfortable, a speculum exam to look for fractured or loosened teeth due to wear is appropriate.

There are many good ways to design a senior diet. The goal is a diet that; meets the basics for nutrition and leaves the horse with something to “graze” food or grass throughout most of the day and night, provides food of a “digestable” particle size, and is a diet that works for your management scheme. Each situation has a lot of factors that may play into what will work best, such as: 

* Pasture companions

* Hay availability

* Where, in the range of tooth attrition your older horse actually is, can they eat some grass but not hay?

* How easy of a keeper are they?  

There is also an array of major food manufacturer websites that have articles about special nutrition, such as low glycemic index foods and higher fat foods, feed calculators online, and the larger companies employ highly educated nutritionists and veterinarians that may provide information and support for owners and veterinarians for consultation about their products.  

Additionally, some health issues can cause loss of muscle mass -PPID (Equine Cushing’s) and abnormal fat distribution –EMS (Equine Metabolic Syndrome). Advanced PPID can be the cause of unnaturally curly or long hair coats and contribute to Insulin dis-regulation these statistically become more prevalent in the older population of horses. There are many foods available in pelleted “senior” form for special health issues so if you have a horse with health issues work with your vet to find the right one for your older horse.

  1. Always make changes slowly over 10-14 days, this allows time for the micro-flora to adapt to new food.
  2. A kitchen food scale is important, every food has a different weight per scoop, and feeding directions is likely in pounds.
  3. Calculate adequate calorie intake to maintain weight. These calories come as… concentrates, forage, pasture and ration balancers. If a horse cannot chew the needed amount of forage then a senior food may be appropriate.  Senior food is usually a “complete” food. This indicates that there is both concentrate and hay both and the food is formulated with sufficient fiber to provide a minimum of “forage” even if no additional hay is fed.  The recommended feeding rate is much larger than the regular concentrate food.  This makes sense since it contains “hay” as well as the concentrate.  Senior foods have amounts for feeding alone or with a minimum recommended amount of hay, so read the bag for each food.

They also have a minimum amount by weight listed that must be fed to “balance” the diet, Usually it is about 6 lbs /1000 lb BW and would require a lot of hay additionally to support a 1000 lb horse…so this means a scoop of senior will not provide the necessary vitamins and amino acids for a balanced diet unless you are feeding a mini!

  1. Forage- all horses need fiber in adequate amounts, usually 1.5-2.0 % of BW, with 1.5% as a minimum for healthy gut function, which includes gut flora.  For example, a 1000 lb horse needs around 15 pounds a day (minimum) of some type of hay; flakes, chopped forage, or pelleted forage.

How do you decide which form? The one they can chew well or pellets! If they are sorting stems out of hay, quidding, or just leaving hay, but eating easier to chew foods, then they probably need pelleted hay and /or a “complete” food. If still eating some hay, but not keeping weight they may be able to eat a moderate amount of senior food and continue to eat hay.  

Hay cubes are not equal to pellets, when soaked they still have a large percentage of 1-2” stems that needs to be chewed in order to be utilized. Remember, wet food to a soft consistency if your horse may gulp it.

There are two big advantages to adding Senior or hay pellets into the diet even if your horse can still chew some hay.

1-      A risk for colic is likely greatly reduced by mixing in some small particle foods.

2-      The small particles will allow a normal population of flora to proliferate. This increases the protein available from hay and fibers for digestion.

For example: 1000 lb horse …generally was an easy keeper until his teeth became worn.

He use to eat 3 lbs of concentrate food, 15 lbs of grass hay and one small pad of alfalfa per day split into 2 meals and had a paddock of short grass to graze between meals (20 lbs of forage total).

Now he has trouble with hay stems and leaves them, he has a few intermittent bouts of loose manure now and then (his veterinarian finds him healthy) but he has a lot of visible hay and oats from the concentrate in his manure…

 Now he will eat…

6 lbs of a “Complete” and “Balanced” Senior food, 10 lbs of timothy pellets, and 3 lbs of Alfalfa pellets and grass (since he can still nip and chew some soft fresh grass at pasture).

I figure about half the weight of the senior complete food as a portion of the daily “hay” ration, and the wetted hay pellets will replace his hay that he can no longer chew. He goes back to being an easy keeper.

Or… for a very senior horse that is a hard keeper and cannot chew even grass anymore…

15 lbs of Senior (based on the ideal body weight and the feeding amounts given by the manufacturer).  Always divide meals so less than 5 lbs per meal is fed for a 1000 lb horse. The more meals you can manage thru the day the better for the horse and the more you will stretch your food dollars, because they will likely get more energy out of the same food if eaten slowly in smaller meals. Large meals tends to cause the stomach to empty prematurely.

  1. horse specific mineral balancer and free choice salt, is recommended by most all feed companies in addition to their foods.  Since balanced foods contain the minimum of daily required minerals for all horses, it is adequate only if the animal; isn’t sweating a lot, isn’t ridden a lot, isn’t stressed...etc.  Extra needed minerals, is made up by what you provide beyond the balanced food. I personally use loose minerals and loose salt in separate feeder tubs in my run in barns, loose salt is especially nice for older horses since their incisors may not be as comfortable as they used to be so, they may not get enough on hot days just licking a block. Red salt/ trace mineral blocks are just that- mostly salt and not equal to providing a “real” mineral balancer.

For me free choice usually works best, because most animals are very good self-regulators when it comes to salt and minerals, but always limit it until you see how much your horse will eat.

If necessary, dole out a few tablespoons or ¼ cup a day for a full sized horse until the novelty has worn off and they are satisfied.

I personally stay away from adding electrolytes or minerals right into food. This is the equivalent of “force feeding”; most animals will eat the food regardless, and it is rare that a healthy horse not in extreme work needs electrolytes daily. Electrolytes can dehydrate your horse if overfed.

Senior horse notes…

  • Choking is a possibility for any horse not chewing food well. If you aren’t sure that your senior horse will be able to chew dry pellets with the tooth he has remaining or if any horse tends to eat big mouthfuls too fast, then covering the pellets with water at feeding time to make a wet oatmeal is a good idea. “Soupier” is usually hard for them to eat.
  • I find that timothy hay pellets are not nearly as “good” to most horses than senior food or alfalfa pellets…so you can use them separately in a pan (wet if need be) for a pasture food that will be eaten slowly. For example…I feed regular hay to my younger horse and a pan of wet timothy pellets to my geriatric (he is 31) in the same pasture and it works well. My younger horse prefers hay and my older guy can’t chew hay. I separate them at “feeding” time twice a day, so my senior can eat his 4 lbs of senior food  and 1 lb of alfalfa pellets slowly during those meals and not get robbed.
  • Management usually consists of figuring out how to leave the senior with a buddy nearby…for grooming over a fence or sleeping, but allowing them plenty of separate time with their food so they can eat slowly.
  • Try not to leave long periods without chewable food to “graze” on.
  • Be cognizant if wetting food that it can sour quickly and if the horse is not eating it –then it may be soured. This is especially true in hot weather. 
  • Senior horses usually require extra protein so most senior foods are a bit higher in protein 12-14%.
  • Look up and learn to judge your horse’s condition by using an Equine body condition scoring system, and use a weight tape to track trends. Try to have your horse gain less than 1/2 pound per day if gaining weight back.
  • Don’t discount the possibility of PPID in older horses, it is statistically very prevalent in horses by their mid-twenties and treatment to control the symptoms can greatly increase your horse’s longevity and quality of life. Talk to your veterinarian sooner rather than later, if you suspect your horse may be affected by PPID. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

4.  My dental question is in regards to EOTRH in a severe parrot mouthed horse. In your research or clinic, do you have knowledge of a horse(s) with severe parrot mouth, where there is complete loss of incisor contact, to be off feed due to EOTRH?

In my understanding of where we are in current research, the pathology of EORTH is now thought to be caused by pressure necrosis of the alveolar ligament. With constant pressure on any single or multiple incisor/s or the first premolar the tooth structure below the alveolar rim places pressure on portions of the thin living alveolar ligament. This ligament is a living tissue requiring circulation to remain as a viable connection between the cement layer of the tooth and the alveolar bone. The bone can remodel under pressure but the tooth is an already mature and solidified structure that does not allow for significant remodeling in the healthy tooth. Thus the living ligament selectively dies and becomes necrotic within the socket. This produces one or more of several clinical clues upon examination such as:

1. necrotic draining pustules breaking through the gum at level of the alveolar rim margin above the gingival attachment, these “bumps” drain pus when gently opened.

 2. The affected tooth starts loosening- with resulting food packing due to motion seen between teeth and significant discomfort during grinding of the tooth or hand rasping.

3. With prolonged infections, eventual sclerosis and a direct bony attachment may form between portions of the tooth and the alveolar bone.

4. With a loosening ligamentous attachment the root sometimes becomes prolific, with layers of bulbous cementation (an attempt by the body to solidify a moving tooth in the bony socket or an inflammatory reaction to the process) and subsequent remodeling and enlargement of the visible shape of the bone surrounding that root.So this would infer that any tooth that has severe unnatural pressure can develop the disease, and secondarily if it is present EORTH is almost always painful to the horse in my experience. 

Clinically, I have not personally seen a case of either maxillary or mandibular prognathism with diagnosed EORTH present, but our knowledge of the pathology would infer that if pressure contact with the bony palate is severe on the lower incisors, or bio-mechanical pressure during mastication caused by the lower incisors trapped behind the upper incisors severe, then over time ligament necrosis is possible.

In any case, start by clinical examination of the length and positioning of the teeth and the surrounding gums and bone and a thorough whole mouth exam and balancing if indicated to rule out other possible obstruction and imbalance issues causing discomfort (horses with conformational malocclusion of the incisors may or may not have properly conformed and opposing upper and lower cheek teeth). If the restriction due to trapped teeth or large hooks or waves is severe, I have seen horses lose a normal interest in food due to pain without disease present yet. Secondly, if EORTH is suspected, obtain a set of radiographic views of each arcade with good resolution and delineating the alveolar ligaments, or lack thereof.  Separate radiographic views of each of the arcades can be readily obtained by open mouth DV and VD views, utilizing a protective tunnel for the digital plate or a set of two 3” long plastic wedges placed in each side of the cheek arcades and in a sedated horse. (It is important to know that teeth are fairly well smoothed and do not have large waves present to preclude damage if imbedding hooks or pressuring high cheek teeth when the horse chews against the wedges.) Adding a slightly oblique view can sometimes allow visualizing the root in a different plane if pathology is questionable in the lower corner incisor teeth.

If EORTH is diagnosed, or an unresolvable obstruction by offending teeth is present, it should likely proceed to a discussion between your equine dental specialist and yourself to weigh the benefits vs. the  problems presented by surgically removing diseased incisor teeth to resolve the EORTH discomfort and prevent damage to the palate. If palatal trauma or entrapment of the arcades is severe enough then extraction to correct mechanically induced pain may be warranted, keeping in mind that if only some of the lower teeth are removed it may increase palate trauma or mechanical pressure by or on the remaining teeth. 

A few of my cases have involved stoic horses whose problems were not noticeable to their owners, but who showed extreme sensitivity to dental prophylaxis on incisors. These were diagnosed using radiographs and subsequently after extractions made a noticeable improvement in mastication and attitude per their owners. So the signs of EORTH in behavior changes is not always clear in EORTH cases, especially if the horses attitude has changed slowly.  As you are likely already aware, a complete turn around in patient wellness becomes apparent in most cases after extraction of all the painful teeth, with horses happily eating all their  grain and hay shortly after the teeth are out. Nipping short grass is, of course, not possible for horses without any front teeth opposing, but for a severe overbite as you describe, there may already be an inability to graze normally. I have noticed that most horses do hang their tongue out a small amount when relaxed if all of the upper teeth are removed.

As a general note;

In managing my cases of non contacting incisor arcades due to maxillary prognathism; regular (2-4 times) yearly grinding of the incisors combined with careful balancing of the cheek teeth may aid in reduction of the palatal trauma over time, and may check rampant caudally curving overgrowth of the upper incisors for some horses, particularly if started early in life. Of course, caution must be practiced at each prophylaxis to protect the vital pulp of the incisors, while doing as much shortening as possible. I have also found that preservation of the height of the lower rostral cheek teeth arcades; the proximal to distal rise of the 300 and 400 arcades to the 306 and 406 teeth and the same of the maxillary teeth, (within normal functional TMJ balance, i.e. not too drastic of a rise), is helpful in providing distance under the palate and managing the incidence of palatal trauma over the long term. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

 5. My horse has a severe parrot mouth. Floating to remove the hooks/ramps is done twice a year but the incisors have been left untouched for more than two years. The top incisors don’t make contact with anything and the bottom incisors make contact with the palate. How do you know when it is time to have their incisors reduced in length? There aren’t any visible sores on the palate but weight loss and shaking the head have become an issue.

It would be difficult for me to give you a specific opinion, without first doing an exam to determine the ability for your horse to touch the cheek teeth for grinding, and the extent of the interference of the incisors. Working on the teeth myself would aloe me to determine how much I would be comfortable removing if shortening is necessary.  So please consider this a general discussion of the obstacles I may consider and a few of the techniques that I might use for a case of severe maxillary prognathism  (parrot mouthed) horse, not necessarily my recommendations for your horse.   Formulating and monitoring a plan for their care can be challenging. The amount of work and accuracy of the work needed lends itself to using electric grinding burrs rather than hand tools for me, but that is a personal preference and although most dental focused practitioners have these tools available incisor work can be done without them.  There are some, rarer yet, cases that cannot be kept functional or comfortable by dental maintenance and then a surgical removal of some or all of the incisors may be a consideration. This is only a decision I would make in severe cases where shortening has failed to be successful and the horse is unable to be made comfortable to eat.

There are also other health issues that may cause what you describe, so I would be remiss if I did not encourage you to have a thorough examination done first with your local veterinarian to rule out other health issues.

Generally starting early in life for this type of malocclusion (as soon as the teeth are beginning to over grow) and likely planning on maximum shortening work 2-4 times yearly on the incisors, while attempting to preserve much of the normal length of the cheek teeth through very conservative work will allow for the best clearance of the lower teeth from the palate and the upper and lower incisors from each other.  Palate contact forms a hardened callous on the palate directly behind the upper incisors where the teeth are pressing against it. Sometimes the interference to normal chewing occurs by the overlapping contact of the incisor teeth themselves with each other. This can be recognized by checking grinding ability carefully through grasping the upper and lower face and moving a relaxed jaw in the chewing motion. Either way, shortening the incisors as much as feasible is usually helpful. Even if the overlap is partial with a bit of incisor occlusion at the corners (03’s) the incisor arcades still need to be level from left to right across the entire set of teeth so that both the  side to side and slight front to back “orbital” motion during chewing is not impinged. If the incisors are longer than normal and occluding at all then they are likely affecting the grind of the cheek teeth.

When starting on an older horse where the incisor length has gotten ahead of a shortening plan I do try to accomplish as much shortening as I consider feasible each visit to make headway, and I would want to see the horse a few times yearly so that there is  3-4 months between visits for the pulp cavity to fill with tertiary dentin for protection, but not so much time that headway in progressively shortening the incisors is lost. I would caution that when I am attempting to do a maximum amount of work on any teeth I almost never actually go by a set measurement of length to remove, because it can be very variable among different teeth and different breeds and ages of horses. Making an assumption that you can remove a set amount may give unexpected results if teeth are shortened quickly assuming you have a “safe” amount of tooth to remove.  I keep an idea in mind of how much my general goal is, but my guide is to watch each tooth carefully for subtle color changes during shortening and to work very slowly. This gives me the best opportunity to do a good amount of work for the horse at each visit but to know when I want to stop shortening and put off additional work for another visit.

 I have seen quite a few horses over the years with incisor trauma from kicks and trailer bumps, fights and collisions with stationary objects, causing a fracture with a severely opened incisor pulp and/or deeply fragmented incisors and a large percentage of these create a pulp stone that plugs the pulp cavity and prevents a root infection on their own.  Cheek teeth fractures tend to not be as forgiving; the roots are multiple and branched and infections from fractures are common.  So I am even more likely to stop work earlier to protect the cheek teeth from accidentally touching a pulp tip.  For teeth that are preventing proper chewing I try to be as aggressive as possible to bring them back to proper occlusion but stop to protect pulp if in doubt. The age of the horse also contributes to the decision of how much shortening I am comfortable to do, young incisor teeth that still have the shelly cusps can usually be shortened quite a bit while working on the edges around the “cup” but as soon as the initial edge is removed, young teeth may have a large pulp closer to the surface than older teeth.

Since the pulp of the teeth may dictate when you have to stop shortening, or you may know when starting work that you will not be doing as much shortening as you wish in a single visit, I work mostly on the longest teeth first to bring them into level and then continue shortening equally so the arcade is as level as possible when I stop.  Level and free lateral movement of the mandible is dictated to a great extent by the path of the incisors which allows normal function for the occlusion or grinding ability of normal balanced cheek teeth and provides for normal apposition of the surfaces of the TMJ. My goal is primarily to relieve incisor trauma to the palate and interference with the other teeth, while keeping in mind that a pulp cavity can be opened from the side of a tooth as well as from the bottom of the tooth.

With respect to the joint and dental imbalances and restrictions… many important facial and proprioceptive nerves, both motor and sensory types of nerves, pass near or within the fascia associated with the TMJ and protecting or improving proper grinding ability allows the least abnormality to the joint function and improves many clinical signs that may be associated with joint nerve irritation or joint soreness directly. While I would agree that perfecting teeth cannot fix all maladies… there are a surprising number of problems that may be associated with imbalances of the teeth,  such as;  head tossing, bucket flinging at meals, disagreeable attitudes about bitting or having ears and face handled, sensitivity at the poll with increased resistance to haltering and tying, all the way up to problems resisting collection and/or flexion in work, resulting in heaviness riding,  stopping at jumps, stiffness in turns…etc… etc, and of course obvious problems eating such a quidding hay, dropping grain and inappetance if uncomfortable to the extreme.  The solution for many horses is to free the restrictions to normal jaw motion while correcting the angles and overall ease of contact of the cheek arcades. This does not necessarily mean the teeth are “smooth” to the extreme.  I am a proponent of conservative smoothing when necessary, but occlusal surface interface angle and quality grind that does not require abnormal lateral motion is by far more important in my opinion.  Over aggressive smoothing with a significant amount of enamel removal may cause accelerated wear beyond the capacity of the horse to erupt replacement crown length.  If cheek teeth are shortened by accelerated wear to the point of not supporting the grinding cycle then TMJ discomfort and the horse’s purposeful disuse of the chewing muscles will likely follow in my experience. Atrophy of those muscle groups can be seen easily in many of these cases.

 With all that said… the balance for the cheek teeth, as well as the height of the overall arcades and angle of the surfaces that occlude must be kept very close to as normal as possible,  because a severe “uphill”  lower  arcade or significantly “long” upper front cheek teeth may “help” by holding the incisors apart; but abnormal heights of some of the teeth in the cheek arcades may also cause uneven wear of the back teeth due to abnormal pressure and problems chewing but also improper opposition of the TMJ’s. This then becomes a factor in my opinion of a host of other secondary problems such as: irritability with the face or ears being handled, poor bit acceptance and contact, poor collection or flexion, habits during eating such as bucket flinging or head tossing, as well as, long term abnormal inter-articular cartilage wear, abnormal forces on the meniscus within the joint and accelerated arthritic changes of the joint. 

So… I would suggest seeking a physical exam, a dental exam and start on needed corrections.  In the short term you may want to consider feeding as you would an old horse with dental problems chewing, so wet hay pellets (not cubes), the consistency of oatmeal to replace some of the hay (by dry weight). And consider a senior or senior low starch, complete food, as appropriate.   If your horse is older with a possibility of PPID, or you know your horse has special health issues it is particularly important that you seek veterinary advice for a diet change.  Using the feeding instructions for the food you choose is important as well. Researching diets for horse with problems grinding food may give you some insight for diet and management. Just a change to hay pellets may drastically increase absorbable calories if there was a previous problem grinding hay. Remember to make any changes to diet slowly over 7-10 days and make increases of absorbable calories slowly as well. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

6. This morning, one of the horses I care for had swelling across the bridge of her nose where the halter rests. The owner has recently hired a new farm hand that uses negative reinforcement. He was working with her yesterday, could he have jerked forcefully enough to injure the bridge of her nose or should I be looking for a different cause? I attempted to palpate for possible fracture but the area is too edematous. He had made the comment about teaching her to back up and I wonder if jerking back on her halter would cause bruising or fracture that could be the source of the swelling.

I am sure that it is possible to bruise tissue across the bridge of the nose or even fracture the incisive bone if enough force is used. However without being present to examine your specific horse I would not speak to this situation in particular. I would strongly suggest an examination in person w your owner's local trusted veterinarian to help determine what needs to be done for this horse if swelling is persistent.

As far as equine nose and facial injuries in general.... 

For any horse with swelling that appears to involve the incisive bone or cartilage, I would likely want to have a set of radiographs to confirm the soundness of the bone before placing any stress on the incisor teeth through the use of a speculum.

It is important to determine if edema is caused by injury to the soft tissue vs bone vs cartilage; or if it is even just a skin irritation due to a reaction from leather or tack cleaner or soaps or even plant particles that may stick on the inside of a soft halter. After external examination, depending on where the swelling and sensitivity is,  I might also include an intra-oral examination of the cheeks and teeth and/or a look into the nostrils.

In case you are interested in some general equine facial anatomy:

The dorsal (upper) area of the equine nose is an outer shell of bone which houses the rostral (forward) and caudal (towards the ears) maxillary sinuses, and the conchal dorsal sinuses: These are air filled sinuses that are above the nasal canals (where the horse actually breathes in) . Some of the upper cheek teeth actually sit under the floor of these and the nasal lacrimal ducts (drain tears) are housed in bone nearby and flow out the end of the nose. Part of the sinuses also house a fairly fragile bony canal running through them that protects a major nerve for sensory function to the entire bone of the upper face. The (conchal) dorsal sinuses are in the center of the nose just under the "bridge" of bone and run lengthwise down most of the upper half of the nose from low forehead level.

The lower structure of the "bridge"  of the nose is made up of bone and cartilage with a relatively fragile area where the incisive bone gives way to the continuation of the cartilage of the nasal septum. This septum divides the the nostrils; right and left and rounds to form the nares or nostrils and nose structurally. This cartilage can be located anatomically via palpating in the normal horse by gently grasping low on the bridge of the nose and wiggling left and right to feel where the points of the incisive bone ends and the cartilage begins. This area is lower than the proper place that a well adjusted halter or over the nose chain should rest. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

7. Why do veterinarians not routinely address the front teeth when floating? If there are obvious points, etc., should these not be addressed as opposed to "allowin them to wear naturally?" If the teeth wore naturally/correctly, there would be no need to float, right? Doesn't floating the back without addressing the fronts leave the mouth unbalanced?

This is a most valid concern in my opinion. It is a complicated discussion so let me use your questions, as you have asked them, to address the issue as I see it.

Why do vets not routinely address floating the front teeth…?

This has several suppositions so let me start by saying that I am a veterinarian and I rarely touch a horse for dental work, which does not get at least some attention, to leveling or shortening or even just smoothing baby’s shelly new front teeth before placing the incisors in a speculum for work in the back. Placing a speculum plate on uneven young incisor teeth is asking to fracture chips off and placing it on very un-level or diagonal teeth is asking to fracture a root on a tall lower corner tooth… not to mention the stress that is transferred back to the TMJ if teeth are uneven and the speculum cannot be opened symmetrically.

I have also followed behind many non-vets who have floated but ignored incisor length and balance, so it seems to be more a question of why this isn’t addressed across the board.

 …if there are obvious points…etc. should these not be addressed?

Again in my experience I would say  emphatically “yes”  they should be addressed… but in addition to addressing the obvious details such as hooked corner incisors or small points, I would add to that and say that the ratio of upper incisor length to lower incisor length and the levelness of the incisors from left to right is even more important  to the proper biomechanical angle and stresses placed on the TMJ,  as well as the angle of incisor teeth overall  with respect to the center incisor (101/201) intersection)  and the TMJ is critical in determining if the horse will not only be comfortable eating, but if the horse will create or, continue to create a depression at the lower 10’s (next to last tooth) and be predisposed to forming  caudal 311 and 411 hooks. (last lower teeth on the left and right)

If anyone practicing equine dentistry has doubts of this try an experiment-  mirror this discussion by accurately and levelly grinding these angle changes on the incisors of a cleaned skull and watch the geometry changes  and forces created at the molars and at the interface of the joint surfaces of the TMJ by increasing the angle of the incisors more and less acutely.  If you really want to become a believer of how detrimental poor incisor balance is to the horse use a filler of thin foam to imitate the TMJ meniscus and use dental marking paper between both sides of the foam to mark the inter-articular forces and look at the pressure points created on the inter-articular protuberances by these changes.

…Should front teeth be allowed to wear “naturally” ?...

I have an eclectic (but somewhat scientific) conclusion about that…I think it makes sense that our domesticated horses these days do not eat from hardscrabble grass areas and pick thru all the rough vegetation that most wild horses must to survive. The domestic horse also has a life span 2-3 times that of most “wild” horses… so I believe they are not wearing enough naturally, given the history of the horse’s  recent (genetically “recent”) living conditions, especially as the horse ages. I have also come to a general opinion, through paying close attention to many of my own populations of patients, that genetic populations that come from areas of the world with softer grasses  (Welsh ponies for example) have smaller incisors for their skull mass than the average horse population.  I see these horses also needing less reduction to maintain what I consider “proper” incisor length and angle.

And lastly you ask … doesn’t floating the back without floating the front leave the mouth unbalanced?

You can probably guess by now that I think it most certainly does cause unbalances in most patients.  For many reasons… eating (grinding) ability or more accurately lack thereof in horses with overly long incisors, riding comfort and normal head carriage during collection via the mandibular positioning,  and TMJ health over the long term (think arthritis and meniscal damage) and comfort of the joint during chewing  (I believe this last point can be reasoned even to the point of comparing muscle atrophy of the muscles of mastication in horses with clinical signs of TMJ sensitivity and correlating those two observations with overall incisor length, upper to lower incisor ratio, angle and left to right levelness.  We even now suspect that a disease that is prevalent in older incisor teeth (EOTRH) is caused by increased pressure on incisor tooth ligaments. This then eventually causes ligament death and necrosis due to inter-alveolar pressure. (see my answer to this month’s first question . It is a nagging question of mine concerning disease (which has been proven by research to be more common in certain populations of Western European Warmblood horses) is partially driven by floating thecheek teeth  without appropriately shortening the front teeth.

And so you ask why aren’t we all in agreement? … 

I think we are just coming into the era of attention and care that teeth and dental balancing deserve for our equine. The newly formed  College of Equine Dental Veterinary Diplomats have now recognized that incisor correction is a part of a thorough examination and prophylaxis in the recent paper written to outline expectations for a thorough dental exam and float. Up until a couple of years ago Equine Dentistry was lumped into the same Board specialty as Small Animal Dentistry.  We are seeing the slow maturation right now of Equine Veterinary Dentistry as a Board Specialty. There are some doctors across the country who have devoted a lifetime to this already and are our “gurus” but I hope that many more doctors (both general Veterinarians and Boarded Dental Specialists) will not only pay attention to the surgery and medicine skills but will come to believe as I do that meticulous balance makes a life changing difference to our patients.  Comfort, joint health and good chewing function affect horses hourly, daily, yearly and on a lifetime basis, most would agree to those premises …now we just need to mature our knowledge to point of more general and accurate consensus among veterinarians, and specialist technicians who are working with veterinarians, on how the actual art and science of balancing should be standardized. Cindy Allen, DVM, Bit O' Magic Equine, Aluchua, Fla.

AAEP Ask the Vet: Broodmare Practices for the Healthy and Subfertile Mare

Broodmare Practices for the Healthy and Subfertile Mare

 

  1.  How can I prevent my mare from getting bred by my stallion as they are extremely buddy sour? We have tried separating them but I feel it becomes a dangerous situation for them

I have given some thought to your troublesome situation. This is an interesting topic for discussion. I see two immediate concerns for you: 1) wanting to avoid physical trauma to both your mare and stallion and 2) not wanting your mare to get bred.

Equine intercourse is a rapid and sometimes violent act. All parties are at risk for trauma during this activity. Furthermore, stallions often get injured when exposed to mares that are not in heat when the mare objects strongly to the stallion’s advances. Letting your mare cohabitate with your stallion could result in trauma to both your mare and stallion at any time and also result in an unintended pregnancy.

If your stallion has a busy breeding season, you may want to have more control over his activities. An injury can really set things back with your stud book. Additionally, if his fertility is sub-optimal you will not want him wasting his “efforts” on breeding your mare if that is not your desired goal. Some stallions need to be on a specific collection schedule to optimize conception for the mares that he is booked to.

There are a few chemical, non-chemical and surgical methods available to reduce conception in the event that a mare will be, or has been, exposed to a stallion. Unfortunately, none of them are foolproof in either preventing conception and/or eliminating estrus behavior during which time your mare will be agreeable to being bred. Some of the methods may reduce the odds of conception, but will not effectively suppress estrus, thus your horses will likely be breeding. Some methods may suppress estrus, but I have found that horses behave with a “where there is a will there is a way” attitude. For example, I have seen some determined stallions try to breed a mare over a fence. Because of these inherent behavioral challenges, most farms that house stallions keep them completely segregated from other horses on the farm.

The equine sex drive and resulting complications in management are the leading reason for the considerable castration rate among males. If your intent is not to retain your stallion as a breeding animal, I would strongly encourage you to castrate him. Likewise, you could ovariectomize your mare. Removing the ovaries from the mare will make her infertile. Interestingly though, ovariectomized mares will often show persistent mild estrus, which might make your stallion a very busy boy. I realize that castrating your stallion may not be an option, but this would likely solve that vast majority of your concerns.

Alternatively, I would encourage you to consider changing your buddy system by adding another mare for your mare and possibly a goat or other type of buddy for your stallion. I have seen arrangements such as these prove very useful. If you are willing to consider separating your mare and stallion, there is another idea to consider. The risk of injury during this adjustment period may be mitigated by the use of long acting and short acting tranquilizers to get them over the separation anxiety.

In any circumstance, I would encourage you to seek input from your farm veterinarian. Your veterinarian should have a good understanding of your goals, management options, know your horse’s personalities and be able to administer appropriate treatments based on what would work best for all of you. Best of luck to you! Holly Mason, DVM, MS, Utah State Veterinary 

 

2.   I have a 2-year-old Molly mule that shows strong estrus behaviors. Will implanting marbles in her uterus help? Or are herbal supplements or other therapies preferred? Cost is a factor. 

I have a real soft spot for these creatures and I applaud you for being a mule owner. Your situation is not unique to molly mules. Dealing with undesirable estrus behavior can be a problematic situation for the owner of any female equid.

Marbles have been used to suppress estrus with mixed results. Some authors report that timing the placement of the marble as close to ovulation as possible has a positive influence on the efficacy. The uterus is also surprisingly good at expelling the marble. These reasons have made marble use overwhelmingly unpopular among horse owners and veterinarians. That being said, the marble would likely be your least cost interventional option.

The most reliable method to suppress estrus is by administering synthetic progesterone. You have two options in this category. The first and most reliable is to administer an oral solution (Regumate) daily. This can be costly and there are human health risks associated with exposure to this product. The second is by administering an intramuscular injection of a compounded long acting progesterone. Depending on the formulation, the injection may need to be repeated every 2-4 weeks. My experience has been that the injectable method is slightly less effective than the oral method. A lot of what determines the treatment depends on the client’s budget and level of expectation. I have used both methods with very acceptable results.

You may hear some people talk about spaying a molly mule. This is a procedure during which the ovaries are removed. I would caution you against this procedure as it rarely eliminates the estrus behavior and in fact often makes it worse.

A no cost method of dealing with your molly mule’s estrus would be to track her cycles on the calendar and limit or reduce your demands on her during times when you know she will be in heavy heat. As a point of reference, most mares are seasonal breeders that begin cycling in early spring and go into winter anestrus around late fall. Ovulation occurs about every 21 days and heat is evident for 5-7 days around the time of ovulation.  

I sympathize with your situation and hope you can find a method that works for you. Good luck! Holly Mason, DVM, MS, Utah State Veterinary 

3.   I have a 5-year-old mare that both her front knees have swelled like tennis balls. What can be applied topically to alleviate the swelling? My second question is that I have another mare (English Thoroughbred) that was coverd twice from a stallion in pakistan. The mare did not concieve in two cycles after a period of 21 days. The veterinarian has ultrasounded the mare and says there is a folicle, which burst after 4 days in which she came back into heat? Any suggestions on what I should do for the mare before she is covered again by the same stallion? 

In regards to your mare with the swollen knees, a diagnosis needs to be determined by a veterinarian in order to decide the best course of treatment. In my experience, the swelling you are describing is unlikely to be relieved by any type of topical treatment alone. Depending on the diagnosis, treatment may include any combination of systemic anti-inflammatory drugs, disease modifying osteoarthritis drugs, intra-articular medication, topical therapy or possibly even surgery. The course of treatment is typically negotiated between the client and veterinarian depending on the diagnosis and expectations of the client in terms of outcome.

In regards to your broodmare, it is not uncommon for a mare to require 2-3 covers prior to conceiving. If you think there is a problem, I would advise having a uterine culture and cytology performed to make sure that there is not an infection present. If her culture and cytology are supportive of an infection, that will need to be addressed with antimicrobial therapy. Most veterinarians will use an ovulation induction agent, such as Deslorelin, to ensure that the mare will ovulate at an appropriate time following breeding to improve the odds of conception. The timing of the administration of this drug is critical and depends on many features of the rectal palpation, ultrasound exam and when the stallion covers her. For the mare that has an over active or prolonged inflammatory response during which fluid is retained in the uterus, intramuscular oxytocin injections are commonly used to encourage evacuation of that fluid. Some mares can be quite challenging to get pregnant and may require additional therapies not mentioned here. I hope you have better luck the next time around. Holly Mason, DVM, MS, Utah State Veterinary 

4. I have just bred my Andalusian mare and am assuming she is in foal. How should I manage     her forage intake to be sure she gets appropriate nutrients and roughage? She is a very, very easy keeper that can easily get fat on hay alone.

This is an excellent question. I am glad that you have given this aspect of your management some consideration. The good news is that if she is already at a reasonable weight and body condition score (BCS), you don’t need to make changes to your feeding program until she finishes her 8th month of gestation. The time of highest digestible energy requirement for a broodmare is during months 9, 10 and 11 of gestation and then through lactation. Energy requirements are even higher during lactation, than they are during gestation.

Forage is the primary feed material required by any horse and a broodmare is no different. Forage consists of dry hay and/or fresh pasture. A good rule of thumb is to keep it simple. Start by giving your mare a thorough looking over to determine her current BCS. The ideal BCS for the average horse is 5/9. However, Andalusians tend to be on the plump end of the spectrum. I believe it would be appropriate for your mare to sit somewhere around a 6-7/9.  It has been my experience that when mares are obese (8-9/9) towards the end of their gestation that they are prone to a more challenging delivery. Obesity also has a negative impact on fertility. You will want to be aware of this if you are planning on re-breeding her.  In addition to BCS, you should document her weight by using a weight tape. Weight tapes are a reasonable method to estimate a horse’s weight. If you use the same tape consistently, you will be able to document changes in your measurements. At certain intervals you should repeat the body condition scoring and weight taping to evaluate if she is gaining or losing weight and to determine if your feeding program is meeting her needs.

When you are feeding a horse to maintain it’s current weight, you should aim to feed approximately 1.5%-2.0% of your horse’s body weight per day. So, if your mare weighs 1200 pounds she should be fed 18-24 pounds of hay daily. I encourage you to weigh your mare’s feed if this is something that you are not already doing. This is the most accurate way to make sure your mare will not be over or under fed. Volume measurements (i.e. a quart or a flake) are not consistent between feed materials.

Easy keepers on good quality hay may benefit from a vitamin/mineral balancer added into the diet. There are several vitamin/mineral balancers available from reputable companies on the market today. This is important to consider because as hay ages the vitamin content will decline over time. The mineral content of your hay will typically vary depending on the type of hay and the quality of the soil it was grown on. Additionally, all horses need free choice salt and fresh water available at all times.

If you wanted a more precise determination of what to feed, you could have your hay sampled and analyzed to evaluate specific constituents such as digestible energy, protein and vitamin/mineral content. For example, alfalfa hay is very high in digestible energy and protein compared to grass hays that are typically lower in both of these categories. Thus, you may need to feed less alfalfa or more grass hay depending on your situation. You could have your veterinarian or a nutrition consultant balance a ration for your mare with the information from a hay analysis. At the very least, you should make a gross evaluation of your hay for quality. Make sure it smells and feels pleasant, is not dusty, is not moldy and there are little to no weeds or debris that have been baled into it.

If your mare is at a reasonable body condition on your current feed program, then you should not need to make any changes until she ends her 8th month of gestation. At this important time, you should add a concentrate to her forage intake. A concentrate is a way to get additional calories, protein, vitamins and minerals into your mare as the foal’s needs are increasing in-utero and while nursing. There are also several reputable companies that produce and market such concentrates. Remember to read the label for the feeding instructions. The label will usually give you an idea of how much to feed on a daily basis depending on your mare’s BCS, weight, stage of production and forage availability.

Use your veterinarian as a resource to help you determine your mare’s weight, BCS and advise on your feeding program. You will be seeing your veterinarian often during the pregnancy for repeat pregnancy evaluations and immunizations that are important during gestation. Good luck! Holly Mason, DVM, MS, Utah State Veterinary 

 5. My mare is due in early July. I am from North Dakota and have vaccinated her now, but have heard that it is good to vaccinate again within 30 days of foaling to give the foal resistance. What about the rabies shot? Should that be done within that 30 day timeframe, or now when I usually do it?

The short answer to your question is yes – booster the rabies immunization. The ability of the foal to fight off illness is profoundly dependent on the immunoglobulins that are passively acquired by consuming the Dam’s colostrum during the first 18-24 hours of life. The reason for the recommendation to booster all of the mare’s immunizations 4-6 weeks prior to the delivery date is to ensure that the highest quality colostrum possible will be available to her foal. The immunity acquired by the foal through the colostrum will be what provides protection during most of the first year of life.

De-worming should also be part of your preventative care strategy for both mare and foal. There are differing recommendations on when to de-worm a broodmare. The foal will naturally consume the mare’s manure to establish gut flora and you will want to limit the foal’s exposure to parasites during this time. Most broodmares will get de-wormed at the same time they get their pre-foaling immunizations and then possibly again more near the delivery date.

Don’t forget to have your veterinarian perform a post-natal exam on your foal on that first day of life. I can not stress enough how important this is!! Part of the exam will be to determine if the foal has received enough antibodies from the colostrum. Foals that have not received enough antibodies are at significantly higher risk of illness. Good luck! Holly Mason, DVM, MS, Utah State Veterinary 

AAEP FAQ: Equine Herpes Virus

Equine Herpesvirus (EHV) - Feb 25th, 13

1. What is equine herpesvirus (EHV)?

EHV are viruses that are found in most horses all over the world. Almost all horses have been infected with the virus and have no serious side effects. It is unknown what causes some of the horses to develop the serious neurological forms that may be fatal.

2. EHV stands for equine herpes virus. It is a family of viruses which are named by numbers such as EHV 1, 3, 4. There are more viruses in this family, but EHV 1, 3, 4 pose the most serious health risks for …….

To date, nine EHVs have been identified, worldwide. Three of these, EHV-1, EHV-3 and EHV-4, pose the most serious health risks for domesticated horses. Equine herpesvirus myeloencephalopathy (EHM) is another name for the neurologic disease associated with equine herpesvirus (EHV) infections.

• EHV-1: Can cause four manifestations of disease in horses, including neurological form, respiratory disease, abortion and neonatal death.
• EHV-3: Causes a venereal disease called coital exanthema that affects the external genitalia.
• EHV-4: Causes a nonfatal upper respiratory tract disease in foals and is uncommonly associated with abortion and rarely with neurological disease.

EHV is a common DNA virus that occurs in horse populations worldwide. The two most common strains are EHV-1, which causes abortion, respiratory disease and neurologic disease; and EHV-4, which usually causes respiratory disease only but can occasionally cause abortion and rarely neurological disease.

Respiratory disease caused by EHV is most common in weaned foals and yearlings, often in autumn and winter. Adult horses are more likely than younger ones to transmit the virus without showing signs of infection.

EHV-1 myeloencephalopathy (EHM) results from widespread vascular or blood vessel injury after damage to the lining of the blood vessels of the blood brain barrier. Neurologic signs result from inflammation of the blood vessles, blood clots, and death of of neurologic tissue. Equine herpesvirus myeloencephalopathy (EHM) cases occur singly or can affect multiple exposed horses. They may or may not be associated with a previous or ongoing EHV-1 respiratory disease outbreak.

3. How does EHV spread?

EHV-1 is contagious and spread by direct horse-to-horse contact via the respiratory tract through nasal secretions. It is important to know that this disease can also be spread indirectly through contact with physical objects contaminated with the virus:

• Human contaminated hands or clothing
• Contaminated equipment and tack
• Contaminated trailers used for transporting horses
• Contaminated wipe rags or other grooming equipment
• Contaminated feed and water buckets

The air around the horse that is shedding the virus can also be contaminated with infectious virus. Although it is known that the virus can be airborne, it is difficult to establish the distance the virus can spread in this manner under typical horse management and environmental conditions.

4. How long can the virus live outside of the horse’s body? This includes on clothing, footwear, walls, buckets, tack, etc…

The virus is estimated to be viable for up to 7 days in the environment under normal circumstances, but remain alive for a maximum of one month under perfect environmental conditions. Most important is to first clean equipment and horse housing areas. (Please Note: It is really important to wash and rinse where you can prior to applying disinfectants.) By cleaning first, this allows for removal or organic material which makes the disinfectants more effective. After this cleaning, follow with a disinfection process. The virus is easily killed in the environment by most disinfectants. Conventional disinfectants and detergents are the best. It is important to perform hand hygiene (wash hands with soap and dry thoroughly or use alcohol-based hand sanitizer) when moving between horses that are grouped separately to avoid spreading pathogens that may contaminate your hands.

5.What are some of the signs of EHV?

After infection, incubation period may be as short as 24 hours, but is typically 4-6 days, but can be longer. EHV-1 typically causes a biphasic (two-phase) fever peaking on day 1 or 2 and again on day 6 or 7. With respiratory infections there is often serous or mucoid nasal and ocular discharge, but not a lot of coughing. There may be some persistent enlargement of submandibular lymph nodes (lymph nodes under the jaw). With the neurologic form there are typically minimal respiratory signs, with fever (rectal temperature greater than 102 degrees F) being the only warning sign. Neurologic disease appears suddenly and is usually rapidly progressing, reaching its peak intensity within 24 to 48 hours from onset of neurologic signs. Clinical signs of the neurologic disease may include:

• Nasal discharge
• Incoordination
• Hind limb weakness
• Loss of tail tone
• Lethargy
• Urine dribbling
• Head tilt
• Leaning against a fence or wall to maintain balance
• Inability to rise

6. How is EHM diagnosed?

Diagnosis of EHM is based on clinical signs and isolation of the virus. Diagnostics performed by your veterinarian may include:

• Nasal swab collection for laboratory examination and detection of virus by polymerase chain reaction (PCR) assay and/or by virus isolation
• Blood collection to detect virus by PCR assay or by virus isolation.
• Blood samples should be collected 2 to 3 weeks apart for levels of antibodies specific to EHV-1.

7. Is it safe to travel with my horse? (i.e. trail ride, horse show, etc.)

Consult with your local and state/provincial veterinarian’s office regarding any newly developed travel restrictions.

Safety and precaution is always recommended, even when an outbreak has not occurred. Biosecurity is important at all times. Please see the AAEP’s recommendations for biosecurity.

8. If I’m involved with hosting an equine event or show, should the event/show continue or should it be cancelled or does it depend on the location of the event?

It is advised to seek updates from the event organizer and from State Animal Health Officials.

9. How do I handle horses returning from events where they may have been exposed to EHV?

Infections other than EHV-1 can also spread by horse-to-horse contact, so keeping a horse with a fever isolated is a very good practice in any case. However, any horse returning from any event should be isolated to prevent the spread of any infectious disease whether there is a fever or not. 

If you handle a horse with EHV-1 and don't wash your hands or change clothing, the infection may be transmitted to other horses. A solution of 1 part chlorine bleach to 10 parts water is effective for decontaminating equipment and environment. (Washing clothing in hot water with detergent and drying in a dryer is adequate and less damaging to clothing.) Click here for more biosecurity cleaning measures.

If your horse develops fever, respiratory signs or neurological signs, immediately notify your veterinarian and do not move the horse or horses in the immediate area. Alert those who have horses in the adjacent area to cease all movement of horses in and out of the facility until a diagnosis is confirmed by testing and a targeted plan for control of spread of disease is developed in consultation with your veterinarian.

For horses that may have been exposed to the infectious agents and therefore at risk for disease, there are some steps to take to minimize the risk of spread of the disease to their home facility. Even if these horses are returning home from events at which no disease was reported, and even if these horses appear healthy, precautions are needed at this time as these horses could bring it home and spread it at their home farm – this is the classic way this disease spreads:

• These horses should be isolated from any other horses when they return to their home facility. Isolation requires housing them away from other horses (i.e. the horse should be stabled in a barn, turn out shed, paddock or another area where there is no contact with other horses), using different equipment to feed, clean and work with them that is used with any other horses, and rigorous hygiene procedures for horse handlers (hand hygiene, wearing separate clothes when contacting the horses, etc.). Please discuss this with your veterinarian.
• We strongly advise owners to call their veterinarians to discuss how long to keep the horses isolated at home, but even if they don't develop fevers this should be at least 14 -21 days.
• These horses should have their temperature taken twice a day and recorded, as elevation in body temperature is typically the first and most common sign of infection – horses with elevated temperatures (101.5 degrees F or greater) should have nasal swabs and blood drawn by your veterinarian.
• If a horse develops a fever and is found to be shedding EHV-1 then the level of risk to other horses on the premises increases significantly. Those affected farms should work closely with their veterinarian to develop a targeted management plan for situation, if it develops.
• The AAEP EHV Control Guidelines can be used by your veterinarian to assist you in developing a more detailed response plan.

It is essential that the isolation facility have supervised oversight by an individual knowledgeable in disease control and quarantine procedures to avoid the possibility of spread of disease agents. When it comes to biosecurity, compliance with the small details of the plan matter and all personnel need to be informed of the plan to avoid inadvertent errors that can lead to spread of disease agents. Your veterinarian can assist you with this.

10. What do we do if we already have a potentially exposed horse on a farm?

It still makes sense to isolate this horse from other horses, even though it may have already been in contact with them. Start isolation procedures to stop further exposure. It is very important not to mix horses from different groups to accomplish this. Try and isolate the suspect horse without moving other horses from one group to another – segregation of horse groups is the key, because this will help you reduce spread if an outbreak starts.

Check temperatures of all horses on the farm twice daily (fever spikes can be missed if you check once daily) and keep a log of these recordings. If fevers are detected, then test for EHV-1. The value of starting healthy horses on an anti-viral treatment when there is no evidence of disease on the farm is questionable. Consult with your equine veterinarian for further guidance.

11. What anti-viral treatments can I use against EHM on a farm? 

If EHM is present on a farm, then the risk to other horses at that farm is greatly increased. Stringent quarantine and biosecurity procedures must be implemented immediately. Treatments may include anti-inflammatory drugs and some horses may require intravenous fluids. Antibiotics may be used to treat a secondary bacterial infection if one develops; however, antibiotics have no effect on the equine herpesvirus itself.

For horses on the farm that develop fever, test EHV-1 positive, or have a high risk of exposure, anti-viral drugs may decrease the chance of developing EHM and the benefit of antiviral treatment of the horse should be discussed with your veterinarian.

12. Is there any value to using booster vaccination against EHV­1 at this time?

Unfortunately, none of the current EHV-1 vaccines carry a label claim for prevention of EHM. More research is needed to identify a vaccine that may prevent this form of the disease. Some of the EHV-1 vaccines have been shown to reduce nasal shedding and in some cases reduce viremia. These products may therefore have some theoretical value against EHM (by reducing viremia), and certainly against spread of the virus. For more information regarding these vaccines, consult with your equine veterinarian.

If horses on the farm are previously vaccinated against EHV-1, the booster vaccination should quickly increase immunity, and perhaps reduce spread of EHV-1 if it is present. Vaccination in these circumstances is controversial. The use of vaccination is therefore a risk-based decision.

13. How long can my horse shed the virus? Is it safe for the horse to return to work/show ring when symptoms clear?

The AAEP EHV Control Guidelines suggests to horse owners whose horse(s) were on the premises of an EHV-1 confirmed case to maintain isolation procedures (primary perimeter) for 28 days after last suspected new infection. 

In the absence of clinical disease, the risk of exposure decreases with time. A shorter quarantine period maybe justified, such as 21 days. If during this time no horse has had any fever (temperature taken at least 24 hours without treatment with non-steroidal drug), abortion or neurologic signs and all exposed horses are tested and have a negative test result using nasal swabs for EHV-1 by real-Time-PCR. There should be compliance with requirements by state animal health officials for duration of quarantine and testing.

14. What methods of prevention can I implement to avoid EHV outbreak and other disease transmission?

Two main methods of prevention you can establish to help avoid disease outbreak on your premises include vaccination and biosecurity protection. 

The goal of vaccination is to induce resistance to infection prior to exposure by producing a strong and durable immune response without inducing clinical signs of disease in the vaccinated animal. While there are several vaccines available for protection against both respiratory disease and abortion as a result of EHV-1 infection, at this time there is no equine licensed vaccine that has a label claim for protection against the neurological strain of the virus (EHM). Consult with your veterinarian for further guidance if you are considering the use of EHV-1 vaccines.

Biosecurity means doing everything you can to reduce the chances of an infectious disease being carried onto your farm by people, animals, equipment or vehicles either accidentally or on purpose. Anything that touches an infected horse or sheds secretions from sick horses has the potential to transfer pathogens to other horses. You are the best protection your horses have.

15. At what point will the “All Clear” be posted and can I start attending events again or can events/shows start operating? 

The EHV-1 virus is a normal occurring virus found in the equine population. All of the reasons that EHV-1 causes these severe neurological signs in some horses is not fully understood. If you are travelling to an event, contact your veterinarian well in advance of departure date to verify what testing is required. Interstate travel may have different requirements and these requirements may vary to each equine event or venue.

There is never an “ALL CLEAR/ NO RISK” when horses commingle. Basic everyday biosecurity is always recommended. Access information from your State Veterinarian related to situations within your area for updates on equine infectious disease situations in your area as well as updates on the AAEP website.

AAEP Ask the Vet: Preparing for Breeding Season

Preparing for the Breeding Season
  1. There are so many things we are supposed to do to our mares 30 days prior to foaling (i.e., vaccines, deworming, etc.). What exactly is 30 days prior considering gestation is 320 to 365 days, since so many horse owners go by all sorts of calendars predicting foaling anywhere from 327 days to 343 days?2. Is HCG a viable option to help stallion fertility?3. All male mammals have nipples, where are they located on male horses?4. At what age do mares eggs start to go bad, for example in humans women over age 40 are more likely to have a child with birth defects?

    1. The last trimester of a mare's gestation is an important period for the final maturation of the fetus. In addition, the mare's body is busy preparing for a successful delivery and lactation. It is generally recommended to schedule the mare's routine vaccinations during the period that falls 4-6 weeks prior to the due date. The normal gestational length of the mare can vary quite a bit, but the average length is 340 days from ovulation. Knowing the prior reproductive history of an individual mare can be helpful; mares tend to have similar gestational lengths from one year to the next. If the history is unknown or if the mare is a maiden, then plan to administer her pre-foaling vaccines six weeks prior to the due date. This will give her adequate time to mount an immune response and have good levels of antibodies in her colostrum that will be protective for the newborn foal.

    2. Subfertility in the stallion can be a very frustrating problem to tackle. There are a myriad of causes of subfertility. Administration of  HCG (human chorionic gonadotropin) to a stallion is useful in determining if the horse's reproductive problems have a hormonal basis. However, treatment with HCG injections has not been shown to improve fertility in the male horse.

    3. This is the most entertaining question of the month! Male horses do indeed have nipples. They are quite rudimentary, and often difficult to see. They are located on the underside of the horse's sheath. It can be nearly impossible to see them in a standing horse, but the next time you have the opportunity to observe a castration of a young colt, you may see them while he is in dorsal recumbency.

    4. It is well documented that ageing has a negative effect on fertility in women. This also holds true for the mare, although the topic is not as well-studied in horses. A mare's fertility begins to decline in her mid-teens. Many factors are to blame for the age-related decline in fertility, but oocyte (egg) quality is ultimately the primary reason. Studies in mares show that oocyte quality is significantly decreased in mares over 19-20 years old. "Birth defects" due to chromosomal abnormalities are not as recognized in older mares as they are in older women. Dr. Kerry Beckman, Prospect, KY

How often should a stallion's sheath be cleaned during the breeding season?

(Cleaning a stallion's sheath during breeding season is an important part of proper management. The horse should be teased so that he achieves an erection, and washed with warm water. Do not use soaps or disinfectants. If the stallion typically takes several minutes between washing and mounting, then drying the penis is not necessary. If he usually mounts immediately after washing, then blotting the penis with a clean paper towel will be sufficient to remove water that could negatively affect semen quality. 

  1. If it is safe to do so, a stallion should be cleaned prior to each breeding, whether it be natural service or semen collection. If the stallion is bred multiple times per day, cleaning him before the first "jump" is usually sufficient for that day. If he is used for live cover, he should also be rinsed off after mating, to reduce the chances of transmitting infection. There is usually no need to clean the stallion's genitals between breeding episodes, even if he does not breed frequently. Frequent washing (even using only warm water), removes the normal micro-organisms that reside on the sheath and penis, which predisposes him to an infection from more potent bacteria. A study has shown that breeding stallions actually have more bacteria on their reproductive parts at the end of the breeding season, most likely due to repeatedly removing the normal flora.


    In summary, a stallion should only be washed when necessary for hygienic natural cover or collection of semen. A normal amount of smegma and bacteria are part of healthy external genitalia. Dr. Kerry Beckman, Prospect, KY

I own a 22-year-old Warm blood mare She had a live birth in 1996. She is in good health. Can I successfully breed her?

You ask a very interesting question, which does not have a straightforward "yes" or "no" answer. There are several factors to consider when breeding the older mare. Many broodmares can successfully produce foals into their mid-twenties. You must take into consideration the overall health of the mare. Conditions such as chronic laminitis, Equine Metabolic Syndrome, Cushings disease, and even chronic lameness can negatively affect the odds that the mare will conceive and carry a foal to term. The mare's reproductive history can also help predict her future breeding success. An aged mare that has carried a foal to term recently has a better chance of becoming pregnant than a mare that has remained barren. Older mares typically have a lower conception rate per cycle (i.e. 30-40%) versus their younger counterparts (that typically have a 60-70% per cycle conception rate). This means that you may need to breed your older mare several times in a season in order for her to conceive. Aged mares are more likely to have reproductive conformation problems than younger mares.  As the mare ages, her reproductive tract slowly succumbs to the effects of gravity, and sinks lower into her abdomen. Also, she may develop tilted vulvar conformation, or have an accumulation of urine in her vagina. All of these anatomic challenges will predispose her to a uterine infection.  Beyond the conformation of the reproductive tract, we also have to consider what is occurring on a microscopic level within the uterus. Older mares can often have scar tissue, cysts, and inflammatory cells within the lining of the uterus, which will make it more difficult or even impossible for her to produce a live foal. 

The crucial first step to determine whether or not you should attempt to breed your older mare is to have a general health exam and a  "breeding soundness exam" performed by a veterinarian who specializes in equine reproduction. This will include a rectal palpation and ultrasound exam, a vaginal and cervical exam, a uterine culture and cytology, and a uterine biopsy. Other tests may be deemed necessary as well. Some clients are hesitant to spend the money on a thorough initial examination, but it will almost always save you money in the long run. A breeding soundness exam will help determine the odds that your mare can become pregnant and carry the foal to term. This will also help your veterinarian know how to best manage the mare before, during, and after insemination.  

It is important to ensure that the stallion you choose is fertile, and has had his own breeding soundness exam performed recently. Live cover and artificial insemination with fresh, cooled semen are preferable. Breeding with frozen semen typically will further decrease the per-cycle conception rate, and is more inflammatory to the uterus than using fresh semen.  

When managing the breeding cycle in an older mare, I believe that "an ounce of prevention is worth a pound of cure." This means that I tend to be very proactive in trying to minimize inflammation and infection that will occur with insemination. The mare needs to have a clean uterine culture and cytology prior to breeding. I try to manage the breeding cycle so that the mare is only bred once, and as close to ovulation as possible. Often, we assist the older mare in clearing the uterine debris and inflammation by lavaging (rinsing out) her uterus 4-8 hours post breeding. Daily ultrasound examinations will help determine the optimal treatment course. If the mare does conceive, the pregnancy should be monitored carefully to ensure the health of the mother and fetus.

Perhaps the mare in question is valuable for genetic or sentimental reasons, but is a poor candidate to carry her foal to term. Advanced reproduction techniques can be used to successfully produce a foal. "Embryo transfer" is the most commonly employed technique, wherein the mare is inseminated, and the resultant embryo is removed from her uterus 6-8 days after ovulation and transferred to a recipient ("surrogate") mare for gestation. This technique has been very successful for obtaining foals from older mares, but does require that the mare have the ability to conceive and maintain a pregnancy for about a week. If the mare's reproductive tract is unable to accomplish this, then "oocyte transfer" can be utilized. In this procedure, an unfertilized egg is taken from the mare's ovary, fertilized, and placed in a recipient mare for the remainder of gestation. This technique is also fairly successful, but will incur higher veterinary costs.  

In conclusion, there are many factors to consider when deciding to breed an older mare. A thorough examination by a veterinarian that is proficient in equine reproduction will help determine your chances of success. Typically, breeding an aged mare will require a higher monetary investment in order to obtain a foal, but can be well worth the time and effort. Dr. Kerry Beckman, Prospect, KY

AAEP Ask the Vet: Gastric Ulcers

Gastric Ulcers
  1. I have a 15-year-old gelding that I am concerned he might have Vesicular Stomatitis. I noticed today while feeding him he was having difficulty chewing. I had given him Bute in his grain a couple of days ago with molasses for some pain in his hooves, which are being treated by a farrier trained in corrective work. When my gelding is being worked alot he has occasional discomfort as this is why we give him bute occasionally and very sparingly. While checking his mouth, I noticed some raw spots on his gums and he seems to be eating very carefully as if it were painful. I have him in with our two miniature horses, which don't seem to be showing any signs. He is also pastured during the day with our mini donkeys. I have not checked them but will tomorrow. Could this be a result of the bute or possible stomach ulcers? Please advise as there has been cases of VS in my location of Colorado. Thank you so much for your time. 

    I would recommend contacting a veterinarian immediately for evaluation of possible Vesicular Stomatitis, which is a viral disease that can cause vesicles and blisters of the lips, gums, nostrils, corners of the mouth, and tongue.  Your veterinarian would be best able to perform a physical exam and diagnostic testing to further investigate this issue.  NSAIDs such as Bute can cause ulceration of the mouth and tongue, but this is rare and usually is a sign of toxicity associated with high doses or chronic use, especially if you are using a tablet or paste that is formulated for oral administration.  Gastric ulcers can cause a horse to become inappetent, especially with respect to grain, but do not cause the mouth pain that you describe. Jean-Yin Tan, DVM, Syracuse Equine Veterinary Specialists, Manlius, NY

  1. I have a 32-year-old warmblood with a history of serious ulcers (before retiring.) He was treated with GastroGuard initially and again when he seemed to have trouble again due to being fed inadequately 12 hrs apart. His diet is now excellent and he is holding weight beautifully. He even has his top line back. He is given omeoprazole powder with his food. Is there any point to that powder? Once the ulcers are treated with Gastroguard, is that all that is necessary?

    First of all, congratulations on successful treatment of his ulcers and getting him to an ideal weight! These are all indications that the initial ulcers have healed. However, having suffered from ulcers twice, I would agree that he is predisposed to developing ulcers and should be kept on whatever preventive strategies are possible. 

    As you mentioned, feeding practices and management are of paramount importance when aiming to prevent gastric ulcers. I would not only recommend small frequent feedings, but recommend that his forage be primarily alfalfa, which contains natural buffers to help with his stomach acidity. It is also important to minimize any changes in routine, and to treat him with medications (specifically,UlcerGard) beginning 3-5 days prior to any trailer rides or stressful events.

    Besides management, it is also ideal to keep your horse on some form of medication or supplement preventative. While it is true that the brand name omeprazole pastes GastroGard and UlcerGard are the only FDA-approved and scientifically proven treatment and preventative, respectively, for Equine Gastric Ulcer Syndrome (EGUS), I understand that keeping him on UlcerGard indefinitely can be cost-prohibitive. You are correct that many other formulations of omeprazole have been tested for efficacy for treatment of EGUS and have shown a lack of significant effect. Therefore, for treatment of ulcers, the omeprazole powder is not likely to be helpful to your horse. That said, scientific studies have not focused on testing medications in terms of their effectiveness as prevention for gastric ulcers. Therefore, veterinary practitioners resort to a variety of medications which are believed to have some positive effect on gastric ulcers, such as ranitidine and compounded omeprazole, for prevention. There are also feed additives and nutraceuticals such as aloe vera juice, buffering supplements, and prebiotic/psyllium products. Due to the small number of published research trials on preventing ulcers, there is no true right or wrong answer in terms of which medication or supplement you use. Most recently, a Norwegian feed additive called ImproWin, which is a combination of B vitamins and salts of organic acids, has been shown in a research trial to assist in equine ulcer healing. I hope you can use this information to formulate a strategy that best works for you and your horse. Jean-Yin Tan, DVM, Syracuse Equine Veterinary Specialists, Manlius, NY

  1. I have a 9-month-old colt weanling that I believe has ulcers. I have contacted the vet thinking he was colicing as he began kicking at his belly. The veterinarian told us it was likely gas colic. He does this every night with his night feeding, he eats a bit, starts getting uncomfortable, drinks water, has more food, drinks more water, kicks at belly scratches/nips at his belly underneath his legs (raises leg and looks like he is scratching). He has access to lucerne hay throughout the day and he is put in an open paddock with a companion mare at night. During the day he is in his own paddock so he can eat without being bothered by the mare. I have stopped training him as it seems to make it worse. My question is: Why only at night does he have this problem and not during day, and how do I treat him? I have'nt been succesful with ulcers as I recently had to put down my 30-year-old this year since no matter what I did, they would not heal. Australian omogaurd costs $85 a tube, which is only 4 days worth of treatment. Very costly when you have to do it for months. Any help would be greatly appreciated.

    I am sorry to hear about the troubles you have been having with your 30-year-old and now with your weanling. The clinical signs of discomfort and chronicity of the issue that you describe do sound consistent with gastric ulcers. However, the only method of achieving a definitive diagnosis to guide treatment would be to perform a gastroscopy. This is a procedure where he would likely be lightly sedated, and a long endoscope would be passed through his nose into his stomach to quantify and visualize the number, location, and severity of the gastric ulcers you are dealing with. The diagnosis will help to guide what methods of treatment could be used and duration of treatment, all of which would have an impact on cost.

    Gastric ulcers are common in young horses and affect up to 57% of foals. Clinical signs may include diarrhea, inappetence, weight loss, teeth grinding, and colic. In particular, horses at this age may also have involvement of the duodenum, which is part of the small intestine closest to the stomach. Treatment, corresponding to the severity of the ulcers, can range from simple treatment with omeprazole (Gastrogard, Gastrozol) which is a proton-pump inhibitor, to compounded treatment with omeprazole, sucralfate (coats the stomach and provides symptomatic relief), and misoprostol (prostaglandin analog which mimics the protective agents of the stomach), to surgery. In addition, you can make some management changes that can help, which is increasing the number of feedings/day when he is not in pasture, and providing a forage source high in alfalfa.

    As far as the cost-effectiveness of treatment, a new study has just been released that shows that treatment with enteric-coated omeprazole (Gastrozol in Australia) is just as effective at treating ulcers at the low 1mg/kg dose as the high 4mg/kg dose. This can result in significant cost savings for you, should you decide to pursue diagnostics and treatment for your foal. Jean-Yin Tan, DVM, Syracuse Equine Veterinary Specialists, Manlius, NY

My horse has a hoof abscess and has been on bute for a month. Do I need to treat for ulcers?

The stressful event and any change in routine brought about by the foot abscess, combined with the use of the non-steroidal anti-inflammatory phenylbutazone, are all predisposing factors for gastric ulcers. Ideally, if the changes can be predicted, a horse should be started on 1mg/kg of omeprazole paste (Merial Gastrogard in the U.S.) beginning 3-5 days prior to the change, to prevent the formation of gastric ulcers. Since you are already a month into treatment, your horse likely has either developed gastric ulcers, or is not going to develop them. Before instituting treatment for possible gastric ulcers, I would recommend a discussion with your veterinarian on any changes you may have noticed to his weight and condition, appetite, and any signs of discomfort that can be associated with ulcers. His age, breed, and personality can also be factors that relate to his risk of gastric ulcers. Definitive diagnosis to determine if he does need to be treated would be achieved through a gastroscopy. Jean-Yin Tan, DVM, Syracuse Equine Veterinary Specialists, Manlius, NY

 

Would gastric ulcers cause a horse to get thumps (horse holds his breath) or wind suck? (View Answer)

Yes, cribbing and wind sucking has been associated with increased numbers of gastric ulcers but we are not sure if there is a causative relationship there, as not all horses that wind suck have ulcers. One of the theories for the association between wind sucking and gastric ulcers is increased comfort when sucking in air, inflating the stomach, and drawing the ulcerated upper portion of the stomach away from the acids below. For this same reason, holding his breath may also provide temporary relief from gastric ulcers. To further investigate the possibility of gastric ulcers, I would recommend a gastroscopy.

Diaphragmatic thumps (synchronous diaphragmatic flutter, or hiccups), however, are associated with dehydration and severe electrolyte abnormalities in horses. If he is experiencing diaphragmatic thumps, immediate veterinary attention with lab work would be warranted. Jean-Yin Tan, DVM, Syracuse Equine Veterinary Specialists, Manlius, NY

AAEP Ask the Vet: Lameness Injuries and Diagnosis

  1. Lameness Injuries and Diagnosis
    1.  Can rotation in the feet be corrected? My vet says, no, but that the coffin bone can LOOK better and the horse can be made more comfortable by proper trimming. However, once rotated, always rotated. Is she correct? 

      Your vet is correct, but it is worth explaining more about the condition of laminitis that leads to rotation of the coffin bone inside the hoof capsule to fully understand why she is correct. The coffin bone is attached to the hoof wall by microscopic structures called "lamellae." The lamellae are sort of like strips of velcro -- one side of the velcro is attached to the hoof wall, and the other side is attached to the coffin bone. Unlike velcro, however, the attachments are permanent. Once one strip is ripped off the other strip, it cannot be reattached. The hoof capsule of the horse is constantly growing and regenerating, but the lamellar attachments do not regenerate to any appreciable degree. This is why permanent damage to the lamellae cannot "grow out" over time.

      Laminitis, or founder, refers only to inflammation ("itis) of the lamellae. The degree of inflammation will vary with each individual case. If the inflammation of the lamellae becomes severe enough, the lamellae will become damaged and start to weaken. Initially, this causes the lamellae to stretch but not break. If the lamellae stretch far enough they become structurally weakened and can no longer support the weight of the horse or oppose the pull of the deep digital flexor tendon at the bottom of the coffin bone. The lamellae will then give out leading to sinking in the first case, or rotation in the second case.

      It can be difficult in some cases of laminitis to determine whether or not permanent structural damage to the lamellae has occurred. The only way to tell for certain in borderline cases is to look at the lamellae under a microscope -- but we do not do this in living horses because taking that kind of a sample causes too much damage to their feet. Instead we rely on post-mortem study of horses who have been euthanized due to laminitis to study these changes. For the practitioner in the field, we can only infer what the status of the lamellae are by closely monitoring parameters we can measure -- the horse's comfort level, venograms, and changes in the xray over time. Unfortunately, changes on an xray happen several weeks after they happen inside the hoof capsule so we are usually playing "catch up" with our trimming and shoeing recommendations. 

      Certain conditions in the foot may also mimic rotation and make the degree of laminitis look worse. A long toe that has begun to flare will give the appearance of rotation (as well as add mechanical stress to the lamellae), but can be corrected with proper trimming. Additionally, severe white line disease can cause separation of the hoof wall from the backside of the hoof "velcro" strip. White line disease can be difficult to treat in severe cases, but it can be improved, and treatment will improve the radiographic appearance of the foot.

      Good luck with your horse, laminitis is a difficult and frustrating disease for all of us. Heather Beach, DVM, Ashford, CT

      1.  I have a gelding that was diagnosed with navicular before he was 3-years-old. The veterinarian said he was probably born with it. I had such high hopes for his horse. The vet said I would probably have to put him down in a couple of years. I have tried shoes and barefoot. Could I send you his X-rays and you tell me what you think? Does any of those supplements help? I can't stand the thought of this situation. Any suggestions would be greatly appreciated. Let me know if I can send the X-rays please. 

        I am able to answer general questions, but not really able to help you with the specifics of your case in this format. I will give you some general information about navicular disease and other thoughts about young horses with serious problems however.

        The first thing you should know is that most horses with navicular syndrome do not have severe lameness. Navicular syndrome is more commonly a performance limiting disease and many horses with this disease can do just fine with light work if they are maintained with shoeing and other medications as needed. It is very common for navicular disease to be present in young horses, especially Quarter Horses, but having significant changes in a horse as young as yours may be an indicator that this is a more severe form of the disease. The navicular bone is a small bone in the heel of the horse. It's job is to act like a pulley, allowing the deep digital flexor to run smoothly around the heel as it attaches to the bottom of the coffin bone inside the hoof of the horse. Disease in this bone is usually caused by changes in the quality of the bone itself -- the bone becomes hard and brittle and can be more easily bruised from concussive trauma associated with riding, especially on harder surfaces. In more advanced cases, the bone can become very thin, and they can develop cystic lesions inside the bone. These lesions tend to be painful because they cause further inflammation and degradation of the bone.

        Therapeutic shoes can help maintain soundness in many of these horses for a very long time. As for supplements, I might consider putting the horse on MSM, but I would not expect this to drastically alter the course of the disease for your horse. Isoxsuprine is a medication often prescribed for horses with navicular disease. It alters blood flow to the bone by dilating the vessels slightly, to allow increased blood flow to the bone. This will help the lameness in some horses, while others do not show any improvement. I never expect isoxuprine (or any treatment) to improve the appearance of the bone on the xray -- I only look for improvement in soundness. I urge people who try isoxuprine to try it for at least 2-3 months to determine if it is helpful to their horse. Anti-inflammatory medications like bute can also be used to keep these horses sound and comfortable, but should be used at the lowest effective dose to minimize side effects. Once a horse is sound enough to do light work with shoeing and medication, I will often use joint injections (either coffin joint or navicular bursa) to help prolong soundness and quiet down inflammation. I really like to find a shoeing prescription and riding schedule that gets the horse as sound as possible first though, because these are the elements that will ultimately be responsible for the long term success of the treatment. It often takes multiple tries with different shoe/pad combinations before you find the one that really works for your horse so I always urge owners to be patient and keep trying. There is an intravenous medication called Tildren that has been used in cases of navicular disease with some success as well. Tildren works by slowing down active bone turnover. It will not work in all cases of navicular disease, and one treatment will not last forever, but it can be a very good option for maintaining soundness in some cases, although do be aware that it is an expensive medication, so it doesn't make sense for every one to try it. Finally, the last option for navicular disease is to have a surgical procedure performed that cuts the nerves to the foot so that your horse does not feel the pain anymore. There are some complications with this procedure, however, and in most cases it will only last for 3-4 years before the nerves start to regenerate and the horse regains sensation and becomes unsound again. 

        The most important thing that you can do for your horse is to have realistic expectations for him. Work with your vet to establish reasonable short term expectations, and find a good farrier who is willing to work with you and your veterinarian. We cannot "cure" navicular disease, we can only manage it. Good shoeing, medication, and a realistic and appropriate work schedule can keep many of these horses sound any happy for some time. Euthanasia would be considered if the horse's quality of life was suffering -- a chronic lameness apparent at the walk that did not respond to shoeing changes or bute, for instance. Heather Beach, DVM, Ashford, CT

        1.  I have an 18-year-old mare that is lame in her back, right leg. The first veterinarian performed four (4) chiropractic treatments to no avail. The second veterinarian determined she was “flexior positive” with the possibility of being bilateral lame and in the hocks. Radiographs helped to determine this diagnosis. What could have caused this and what are her options for treatment? 

          It is quite common for horses of any age, but particularly older horses, to have a bilateral (meaning both hind legs are affected) lameness that is associated with their hocks. It is also quite common for them to present like your horse does with only one leg appearing to be lame at first glance. This is due to degenerative joint disease of the joints of the hock, resulting in arthritis. The hock joints are a very common site for arthritis in horses, but the good news is that there are many treatment options available and most horses respond very well to treatment of these joints.

          Arthritis in the horse results from a variety of factors. It typically starts with some inflammation in the joint, either because of trauma, repetitive stress from high intensity exercise, conformational defects that put abnormal stresses on the joint, or as part of the normal aging process that we all go through. As time goes on, the inflammation will cause the joint fluid to become thin and provide less cushion and nutrients to the cartilage within the joint. As this process continues, it stimulates bony growth at the edges of the joint that initially appear as "bone spurs." The degree of arthritis present in the joint will depend on the amount of inflammation and the degree of cartilage erosion present. It is important to know, however, that horses may be sore and have positive flexion tests even when they are at the early stages when very little arthritis is present. Conversely, many horses that are at the end stage of hock arthritis are quite sound, because the joint is stabilized and the bone is no longer actively turning over anymore.

          Treatment options will vary and will depend on your budget, the degree of lameness and severity of arthritic changes in the horse, whether or not there are other sources of lameness in the horse, as well as the athletic demands of the horse. A pleasure horse that goes on light easy trail rides on the weekends may do well with just a little bit of phenylbutazone (bute) given before and after a ride in order for her to stay comfortable and be able to do her job pain-free. A more athletic horse may need more targeted therapies. Some horses will respond favorably to a systemically administered joint product such as Legend or Adequan. These are good first options for horses that do mild to moderate exercise, and have mild to moderate lameness issues, or for horses that have lameness issues in multiple joints. Legend is a product that your veterinarian gives intravenously, and is made from hyaluronic acid, which is a component of joint fluid. Adequan is given intramuscularly and is made of a chondroitin sulfate precursor, called polysulfated glycosaminoglycans (abbreviated PSGAGs). Both products are thought to work by down regulating inflammatory mediators in the joint, but there is only limited data available about exactly how these products work. The final option to treat hock pain is with injections of medications directly into the joints of the hock. This is a more direct way of treating the pain and inflammation within those joints. Typically this treatment is done with a corticosteroid and a synthetic hyaluronic acid. Hock injections are very effective at treating pain in the hocks and the effects typically last for 6 months to a year for most horses, although some horses may show symptoms again sooner, and others will not need to be retreated again after the cycle of inflammation is stopped once.

          There are a few more options for treatment of very advanced cases of hock arthritis -- it would probably be best to get a consultation with a veterinary surgeon before considering more advanced options, and in most cases I would only consider those treatments if the horse failed to respond to standard hock injections first. You should discuss all these options with your veterinarian before you decide which treatment option to pursue. Most horses with arthritis will also benefit from regular, low intensity exercise to help keep them moving and fit as well. Heather Beach, DVM, Ashford, CT

    2.  I have an older gelding that has arthritis in his stifle joints. Other than Glucosamine andChondroitin sulfate, what else can I do to keep him comfortable? 

      Oral joint supplements can be helpful for arthritis cases, but often times they need a little something else to really help control the pain and inflammation. Giving the lowest effective dose of bute is a great way to make an older horse feel better while minimizing side effects. I usually prescribe a twice a day regiment for a few days, then back down to once a day, then every other day. I ask the owners to notice how the horse responds and to see if they still see a positive response at the lower doses. Often times, the horse will end up on one gram of bute per day, and do very well on that for a long time. In cases where there is a strong concern for side effects due to bute, Equioxx can be substituted instead. 

      Beyond just giving an anti-inflammatory medication like bute, I will also use some of the injectable products like Legend or Adequan in older horses with significant arthritis. Each of these products requires a three week loading dose phase, then a maintenance dose. Not every horse responds the same to these products, but if they are going to have a favorable response, it usually happens during the loading dose phase, which makes it easy to determine whether or not to continue with the maintenance dose.

      Finally, arthritis tends to respond well to low level exercise. If your horse is retired, consider going on some walks with him. A nice leisurely 15 to 20 minute hand walk per day could be good for both of you, and gives you some extra time to spend with your older horse. If you can, try to make sure your horse has access to plenty of turnout and avoid big steps in or out of his stall so he doesn't have to really pick his legs up to get in and out. Heather Beach, DVM, Ashford, CT

AAEP Ask the Vet: Preparing for a New Foal

Preparing for a New Foal
  1.  I am an owner of an equine facility. I require my boarders to have appropriate vaccines instructed by our veterinarian. Many of our boarders haul in and out for events, hence exposed to different environments. However, it is not local protocal to require proof of vaccines for horses that are hauling in for lessons or an event held at my facility. How do I assure my boarders that haul in horses do not put the board horses at risk of additional exposure without proof of vaccinations? I am also concerned about diseases to broodmares that are present at my facility. 

    This is a good question and a common concern in facilities with many horses that come and go. Couple that with haul-in lessons and shows or events that occur at your facility, it can get complicated. I will give you some recommendations that you might want to consider. 

    It is widely accepted and usually required that all horses coming to a facility for an event or show should have a negative coggins test within 12 months. This should not be difficult to require. For return clients, such as those taking lessons, you can keep a copy of the coggins in your file, and request a copy annually.

    Vaccine requirements are a bit more difficult. To keep this simple, I would limit vaccination requirements to Influenza and EHV1 and EHV4 (equine rhinopneumonitis). There has been much press about EHV outbreaks at racetracks and equestrian events. There are event facilities in my area (Texas) that require proof of vaccination within 6 months. FEI regulations are to be vaccinated no closer than 21 days before a competition and no later than 6 months.

    These two viral infections are highly contagious and have caused quarantine of affected facilities. Vaccine protocols can vary for other diseases and you likely do not want to impose your requirements on those whose veterinarian might have a different protocol. For example, some veterinarians may recommend Strangles vaccination (another respiratory contagious disease) for all show horses. Others may consider those over 5 years old, or, those that have had the disease unnecessary to vaccinate.

    EHV is a cause of abortion in mares, and it is common to vaccinate pregnant mares at the 5th 7th and 9th month of pregnancy. Just one other reason you might want to require all horses entering your facility to have proof of vaccination within 6 months.

    Bottom line, you can require whatever you wish on horses coming to your facility. You can make it so complicated that you lose business, or, rational requirements will keep your boarders happier and help minimize disease outbreaks. Proof of influenza/rhinopnuemonitis vaccine is not overbearing. This would require an updated passport, or a simple invoice from the riders veterinarian that states what vaccine was given and the date administered. 

    Your question could open a can of worms about vaccine protocol and shows or events. I think this is a practical way to handle your concerns and hopefully keep your boarders happy. Mark Haugland, DVM, DACVS, The Woodlands, Texas

    1.  I have been using Diatomaceous Earth as a daily dewormer. My veterinarian is suggesting adding Equimax and then Quest paste. I was reading about kill overload of dead worms. The worm fecal egg count (FEC) is 115. Do you see any concerns? Would there be any concerns for also using this same routine on a broodmare? 

      Today much more emphasis is placed on individual animal deworming programs as opposed to herd deworming programs, which has been the standard over many years. There is concern of resistance to dewormers and there is abundant evidence to prove this resistance.

      Diatomaceous earth is considered ineffective at controlling parasite load in horses. There are few concerns about using diatomaceous earth, but it is not recommended as a parasiticide. You may ask, if it is not effective then why is the fecal egg count 115, which is considered a light shedder? This would suggest that your horse has good immunity and should only need deworming twice annually. The moxidectin or ivermectin products are a good addition as recommended by your veterinarian. This will also kill bots and, if you get the product with praziquantal, tapeworms are taken care of as well. 

      This program is safe for a broodmare, but the fundamental aspect of your question is parasite control. Guidelines for this are based on a fecal egg count reduction test. You have obviously done this in the horse that has a 115 count. However, deworming schedules change depending on the egg count. For example:

      Light shedder: 200 or less

      Moderate shedder:  200-500

      Heavy shedder:  greater than 500

      Based on the egg count, your veterinarian will prescribe a deworming program tailored to the specific horse. In short, the higher the egg count, the more frequently you should deworm. Therefore, the program advised for the horse in your question could be different than one prescribed for your broodmare or any other horse. It all hinges on the egg count. Consult your veterinarian for his/her protocol on egg counts for your farm. He/she will then analyze the results and tailor a program for all your horses based on which category the individual horse falls into. Mark Haugland, DVM, DACVS, The Woodlands, Texas

      1.  My question pertains to when is the best time to geld a colt. I live in New York with real winters and would like to get my now 9-month-old colt gelded before spring is in full swing. I have contacted my local equine veterinarian to set up a date but was told it was too cold and needed to wait until it warms up. I asked what would be suitable temps and didn't receive a proper answer just that it be warmer when the ground isn't frozen. With that said, there will be mud everywhere and infection risks will increase. I do have shelter for my horses so the procedure wouldn't have to be performed outside in the weather or on frozen ground. Yet they refuse to perform castrations and didn't schedule for an appointment. I was told I could bring him into the clinic and have it done there however, that isn't an option. My question to you is can you give me an idea what temperatures would be needed for getting my colt gelded? 

        It is best to castrate when the temperature is above freezing. Remember, the horse will need exercise and possibly hydrotherapy on the area to minimize swelling and pain. Your veterinarian gave you the correct advice to wait for warmer weather or perform the surgery at the hospital. You may have an enclosed area but it may not be acceptable for recovering a horse from anesthesia. Your veterinarians recommendation has your horses best interest at mind. Remember, castration and anesthesia is a stressful event for a horse. Cold weather, particulary in your area of the states, are experiencing unusual cold, which adds to the stress and can be as likely a cause for infection as mud in the spring. I live in Texas and have a castration scheduled for today (January 24). We have rescheduled that procedure due to cold weather and ice. Our temperature is only in the upper 20's. Your veterinarian is giving sound advice. My personal opinion is that 12 to 18 months of age is the best time to castrate unless the horse is unruly and a danger to himself or other horses. Mark Haugland, DVM, DACVS, The Woodlands, Texas

        1.  We all know that blanketing a horse in the winter is a difficult decision sometimes, especially if it is a mare in foal. Is this a safe option? Also, a blanket flattens the winter coat. What I\'ve never seen answered is how long does the coat take to "fluff" back up? 

          There is no exact answer to how long it will take for the hair coat to "fluff" out after blanketing. Hair coat during the winter months is largely determined by length of daylight and ambient temperature.  Other factors include grooming practices, breed, some medical conditions and some medications. It is safe to blanket a broodmare but advised to remove the blanket when close to foaling. A horse that is blanketed daily when the temperature is below 40 degrees and is groomed daily can take 2 to 4 weeks to "fluff out". If you only blanket intermittently, say only when a freeze is expected, then the hair coat will stay dense. In southern climates, where I am, broodmares are generally not blanketed. In harsher northern climates, many broodmares are blanketed daily and moved into a warm enclosed foaling stall 2 to 4 weeks prior to delivery and the blanket is removed. I have seen mares foal with a blanket on, but this is not recommended as limbs can become entangled in the straps and it can be more difficult for the foal to nurse, not to mention trapping its neck in the straps. Hope this helps. Mark Haugland, DVM, DACVS, The Woodlands, Texas

AAEP Ask the Vet: Preparing for Breeding Season

Preparing for the Breeding Season
  1.  1. There are so many things we are supposed to do to our mares 30 days prior to foaling (i.e., vaccines, deworming, etc.). What exactly is 30 days prior considering gestation is 320 to 365 days, since so many horse owners go by all sorts of calendars predicting foaling anywhere from 327 days to 343 days?2. Is HCG a viable option to help stallion fertility?3. All male mammals have nipples, where are they located on male horses?4. At what age do mares eggs start to go bad, for example in humans women over age 40 are more likely to have a child with birth defects? 

    1. The last trimester of a mare's gestation is an important period for the final maturation of the fetus. In addition, the mare's body is busy preparing for a successful delivery and lactation. It is generally recommended to schedule the mare's routine vaccinations during the period that falls 4-6 weeks prior to the due date. The normal gestational length of the mare can vary quite a bit, but the average length is 340 days from ovulation. Knowing the prior reproductive history of an individual mare can be helpful; mares tend to have similar gestational lengths from one year to the next. If the history is unknown or if the mare is a maiden, then plan to administer her pre-foaling vaccines six weeks prior to the due date. This will give her adequate time to mount an immune response and have good levels of antibodies in her colostrum that will be protective for the newborn foal.

    2. Subfertility in the stallion can be a very frustrating problem to tackle. There are a myriad of causes of subfertility. Administration of  HCG (human chorionic gonadotropin) to a stallion is useful in determining if the horse's reproductive problems have a hormonal basis. However, treatment with HCG injections has not been shown to improve fertility in the male horse.

    3. This is the most entertaining question of the month! Male horses do indeed have nipples. They are quite rudimentary, and often difficult to see. They are located on the underside of the horse's sheath. It can be nearly impossible to see them in a standing horse, but the next time you have the opportunity to observe a castration of a young colt, you may see them while he is in dorsal recumbency.

    4. It is well documented that ageing has a negative effect on fertility in women. This also holds true for the mare, although the topic is not as well-studied in horses. A mare's fertility begins to decline in her mid-teens. Many factors are to blame for the age-related decline in fertility, but oocyte (egg) quality is ultimately the primary reason. Studies in mares show that oocyte quality is significantly decreased in mares over 19-20 years old. "Birth defects" due to chromosomal abnormalities are not as recognized in older mares as they are in older women. Dr. Kerry Beckman, Prospect, KY

    1.  How often should a stallion's sheath be cleaned during the breeding season? 

      Cleaning a stallion's sheath during breeding season is an important part of proper management. The horse should be teased so that he achieves an erection, and washed with warm water. Do not use soaps or disinfectants. If the stallion typically takes several minutes between washing and mounting, then drying the penis is not necessary. If he usually mounts immediately after washing, then blotting the penis with a clean paper towel will be sufficient to remove water that could negatively affect semen quality. 

      If it is safe to do so, a stallion should be cleaned prior to each breeding, whether it be natural service or semen collection. If the stallion is bred multiple times per day, cleaning him before the first "jump" is usually sufficient for that day. If he is used for live cover, he should also be rinsed off after mating, to reduce the chances of transmitting infection. There is usually no need to clean the stallion's genitals between breeding episodes, even if he does not breed frequently. Frequent washing (even using only warm water), removes the normal micro-organisms that reside on the sheath and penis, which predisposes him to an infection from more potent bacteria. A study has shown that breeding stallions actually have more bacteria on their reproductive parts at the end of the breeding season, most likely due to repeatedly removing the normal flora.

      In summary, a stallion should only be washed when necessary for hygienic natural cover or collection of semen. A normal amount of smegma and bacteria are part of healthy external genitalia. Dr. Kerry Beckman, Prospect, KY

      1.  I own a 22-year-old Warm blood mare She had a live birth in 1996. She is in good health. Can I successfully breed her? 

        You ask a very interesting question, which does not have a straightforward "yes" or "no" answer. There are several factors to consider when breeding the older mare. Many broodmares can successfully produce foals into their mid-twenties. You must take into consideration the overall health of the mare. Conditions such as chronic laminitis, Equine Metabolic Syndrome, Cushings disease, and even chronic lameness can negatively affect the odds that the mare will conceive and carry a foal to term. The mare's reproductive history can also help predict her future breeding success. An aged mare that has carried a foal to term recently has a better chance of becoming pregnant than a mare that has remained barren. Older mares typically have a lower conception rate per cycle (i.e. 30-40%) versus their younger counterparts (that typically have a 60-70% per cycle conception rate). This means that you may need to breed your older mare several times in a season in order for her to conceive. Aged mares are more likely to have reproductive conformation problems than younger mares.  As the mare ages, her reproductive tract slowly succumbs to the effects of gravity, and sinks lower into her abdomen. Also, she may develop tilted vulvar conformation, or have an accumulation of urine in her vagina. All of these anatomic challenges will predispose her to a uterine infection.  Beyond the conformation of the reproductive tract, we also have to consider what is occurring on a microscopic level within the uterus. Older mares can often have scar tissue, cysts, and inflammatory cells within the lining of the uterus, which will make it more difficult or even impossible for her to produce a live foal. 

        The crucial first step to determine whether or not you should attempt to breed your older mare is to have a general health exam and a  "breeding soundness exam" performed by a veterinarian who specializes in equine reproduction. This will include a rectal palpation and ultrasound exam, a vaginal and cervical exam, a uterine culture and cytology, and a uterine biopsy. Other tests may be deemed necessary as well. Some clients are hesitant to spend the money on a thorough initial examination, but it will almost always save you money in the long run. A breeding soundness exam will help determine the odds that your mare can become pregnant and carry the foal to term. This will also help your veterinarian know how to best manage the mare before, during, and after insemination.  

        It is important to ensure that the stallion you choose is fertile, and has had his own breeding soundness exam performed recently. Live cover and artificial insemination with fresh, cooled semen are preferable. Breeding with frozen semen typically will further decrease the per-cycle conception rate, and is more inflammatory to the uterus than using fresh semen.  

        When managing the breeding cycle in an older mare, I believe that "an ounce of prevention is worth a pound of cure." This means that I tend to be very proactive in trying to minimize inflammation and infection that will occur with insemination. The mare needs to have a clean uterine culture and cytology prior to breeding. I try to manage the breeding cycle so that the mare is only bred once, and as close to ovulation as possible. Often, we assist the older mare in clearing the uterine debris and inflammation by lavaging (rinsing out) her uterus 4-8 hours post breeding. Daily ultrasound examinations will help determine the optimal treatment course. If the mare does conceive, the pregnancy should be monitored carefully to ensure the health of the mother and fetus.

        Perhaps the mare in question is valuable for genetic or sentimental reasons, but is a poor candidate to carry her foal to term. Advanced reproduction techniques can be used to successfully produce a foal. "Embryo transfer" is the most commonly employed technique, wherein the mare is inseminated, and the resultant embryo is removed from her uterus 6-8 days after ovulation and transferred to a recipient ("surrogate") mare for gestation. This technique has been very successful for obtaining foals from older mares, but does require that the mare have the ability to conceive and maintain a pregnancy for about a week. If the mare's reproductive tract is unable to accomplish this, then "oocyte transfer" can be utilized. In this procedure, an unfertilized egg is taken from the mare's ovary, fertilized, and placed in a recipient mare for the remainder of gestation. This technique is also fairly successful, but will incur higher veterinary costs.  

        In conclusion, there are many factors to consider when deciding to breed an older mare. A thorough examination by a veterinarian that is proficient in equine reproduction will help determine your chances of success. Typically, breeding an aged mare will require a higher monetary investment in order to obtain a foal, but can be well worth the time and effort. Dr. Kerry Beckman, Prospect, KY

Ask the vet: Tendon & Ligament Injuries and Rehabilitation.

Has your horse experienced a tendon or ligament injury? Pose your questions on the topic of tendon and ligament injuries and rehabilitation for our AAEP expert, Dr. Rebecca Linke.

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Question: Our 13-year-old Holsteiner tore his left hind oblique sesamoidian ligament. This was diagnosed in early June following a year long quest to determine the cause of a transitory lameness (and injections to many joints including neck, SI joints, stifles, hocks and coffins). Treatment consisted of two sessions of shockwave therapy that were 2 weeks apart and hand-walking for 6 weeks. Tack-walking was then for an additional 4 weeks and a slow build-up of work. He is now up to a full 45 minutes of flat work including trotting and cantering. How long should it be before we can get back to jumping? He was being used as an equitation horse doing 3'6" to 4' medals. Following an injury like this, can he ever be expected to go back to the same level of competition?
Answer: 
This is a question we hear a lot: "will my horse ever return to the work he was doing prior to his injury?" Unfortunately, there is no way to predict which injuries will recur and which will not. It sounds like you and your veterinarian have done the right thing for your horse so far, combining rest, gradual return to work, and shockwave therapy. Continue to work with your veterinarian to determine when is the best time to reintroduce jumping, starting with ground rails and low cavaletti and working up to a goal determined by your veterinarian. The more gradual the return to jumping, the better for your horse. I haven't been able to find a percentage of these injuries that recur, but unfortunately Ross and Dyson (Lameness in the Horse, 2003) report that "the incidence of recurrence of oblique distal sesamoidean ligament injury is high". Because of this, you and your veterinarian may decide that it is best for your horse not to try to return to his previous level of athleticism, or perhaps even find another job that is less physically demanding.
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Question: I live in South Africa and this morning my veterinarian recommended your site in regards to which boots to use on a horse that had a deep superficial flexor tendon injury on his near fore just over a year ago. He was rested for almost 9 months and given PRP treatments three times. I was told the AAEP recommends a certain type of boot for work after this kind of injury. His tendon is cool to the touch and unless one is an expert one would not see that there had been such a drastic injury. I intend to have him scanned again as the thought is to put him back into racing, or is this a very bad idea? Your comments would be much appreciated. 
Answer: 
I am a member of AAEP but I am not an employee. However, AAEP does not endorse products of any kind. I have merely volunteered to answer questions on this topic because I feel that I have had some experience with these types of injuries during my veterinary career. 

It sounds like you have done everything you could for your horse in the hopes of getting him back to the racetrack. I would absolutely agree with having an ultrasound performed on him before he is cleared for this kind of work. One thing you haven't mentioned in your question is whether your horse is a Thoroughbred or a Standardbred, as this may affect whether he is able to return to racing and how successful he may be there. The majority of my experience is with Standardbreds, and in my experience, they have moderate success in returning to racing, even with as severe an injury as you have described. My other question is whether the injury involves the deep digital flexor tendon as well as the superficial digital flexor tendon; you described it as a "deep superficial flexor tendon injury," which I must interpret as being deep within the superficial digital flexor tendon, although that tendon is not usually very thick. Without seeing the original ultrasounds and also the current scans, I'm afraid I can't tell you what his prognosis is for returning to racing. Equine Sports Medicine and Surgery (Hinchcliff, et all, 2004) recommends Dalmar support boots for use after tendon injuries. These boots are designed for use in the exercising horse, but I don't know if they are compatible with horses that are racing, as that is one of the highest levels of performance. If you choose to try these boots on your horse, I recommend that you investigate how he works in the boots extensively before asking him to race in them.
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Question: My 17-year-old Quarter horse mare bowed the tendon low in her right hind leg in May of this year. Our vet completed a sonogram which revealed an already healing lesion. She has been confined to a small turnout area and separated from the other two horses for the last 5 months. There is some swelling at the fetlock joint, but the leg has never been hot. We applied liniment and polo wraps for 4 weeks. She is showing improvement, especially in the last 3 weeks with being turned out in a small area to graze alone. My vet has suggested re-evaluating in December and proceed from there. Any other suggestions, supplements, treatments we may have missed?
Answer: 
Tendon injuries can be frustrating because they take a long time to heal, may or may not resolve ultrasonographically, and may carry the risk of reinjury for a significant time after the original injury. There are a few therapies that are used to try to increase healing and decrease the length of time needed to return to work, but there is really no safe way to rush a tendon injury. Your veterinarian can discuss with you whether your mare is a good candidate for treatments such as stem cell therapy and extracorporeal shock wave therapy. Supplements are available that claim to support tendon and ligament health, and certainly some supplements, such as antioxidants, support the general health of the animal, but supplements are not a substitute for proper veterinary care. Some of these injuries respond best to conservative therapy, such as time off and then slow return to work, with or without nonsteroidal anti-inflammatories, and your veterinarian will be best able to determine the best course for your mare.
4
Question: My horse has continued with bouts of reoccurring lameness. I would find swollen hind fetlocks and would commence to ice, bute, wrapping and rest. She would be fine and I would start her back on light work, but after several times of the lameness coming back, I contacted my veterinarian to do a work-up. An ultrasound showed slight tearing with no noticeable difference right to left in the SDFT as far as swelling. She was sent to the paddock for the next two (2) months, to begin hand walking in one month. He administered ace to keep her calm and DMSO on the joint capsule. When I read up on this type of injury, it seems that it can easily reoccur once it has been weakened. We do nothing more than walk, trot, canter in the ring and the mare has five (5) acres of turnout. Would stem cell or some other type of therapy give me a better chance for recovery?
Answer: 
This is also a good question, but more information is needed to be able to answer. First of all, how old is your horse, and how long have the bouts of lameness been going on? How long would the bouts of lameness last? Certainly tendons and ligaments that have been injured or have shown fiber disruption are often prone to reinjury but unfortunately, it is impossible to predict which ones are more likely to reinjure. Certain factors, such as the severity of the original injury and the intensity of the work program that your mare returns to may have an effect on whether or not she may reinjure her tendon. Your veterinarian would be best able to assess this injury both by how lame your mare is and also how much disruption there is in her tendon, and help you decide whether this is a case that would benefit from stem cell therapy or not. Often if there is a small amount of tearing or fiber disruption there may not be a "hole" into which to inject something like stem cells or PRP, and the injury can successfully be managed conservatively, as you're doing.
5
Question: I have a 4-year-old mare that sustained a puncture injury to the back of her pastern. It went TO the tendon but not through the tendon. Subsequently, an infection popped an abscess at the top of the tendon sheath, which allowed us to drench the length of the wound and the sheath with antibiotic fluid. We did this for several days in a row until the wound did not open through. She was on stall rest and daily bandage changes with several courses of antibiotic treatments. She apparently had infection off and on for at least 3 or 4 months. During this time she was also on higher doses of bute that tapered off along with Ulcergard since she lost a lot of weight. 

She has been ultrasounded 3 times and one of my vets believes she will make a full recovery. The other vet is hoping for pasture sound and pain free. The ultrasound does not show any significant ligament damage but the last one showed a couple of areas that were still healing deep within her leg. Treatment was to leave her on pasture rest for 6 months and then start light riding. 

My concern is the fetlock is much larger on the injured side and also the pastern angel is steeper. I'm not sure if there is something else I should be doing. The vet thinks the larger fetlock is due to scar tissue and doesn't seem to be worried about it. But it does come and go in size and is not painful when palpated. The entire area seems mostly pain free. She does still slightly favor the leg when trotting or slight loping. She won't lope for a long distance but still does buck on occasion. This horse was being ridden at the time of injury in February 2013. Is there anything else I should try or be doing? 

When she was injured in February of 2013, she spent 5 months in a stall with daily dressing changes. It took this long for the initial wound to close. This was up and down period with varying degrees of pain for her with swelling. She was on multiple antibiotics off and on during this time to treat both aerobic and anaerobic bacteria. She was on bute the entire 5 months. Since July she has been pastured. She has responded well to all treatments.The two vets we use are partners in the same practice and both have seen her.
Answer: 
That sounds like a very serious injury and one that may be difficult to recover fully from. My main concerns with this injury are the extensive and lengthy infection and the change in pastern angle. The swelling in the fetlock may be due to either scar tissue or edema caused by decreased circulation, which may be a result of the original injury. It sounds like you and your veterinarians have taken the best possible care of this mare, but it may be difficult to be sure that the infection is completely cleared up, even after all your hard work. I am concerned that the swelling is still changing, rather than just staying one constant size, but the fact that it doesn't seem to bother your mare when you palpate it is a good sign. My concern with the change in pastern angle is that if the fetlock is dropping, it may indicate damage to the suspensory apparatus. With regards to further treatment, it sounds like you and your veterinarians are doing just about everything this mare could need for a successful outcome. Shockwave therapy may help at this point, but without seeing the patient and the ultrasound images, it's difficult to say what her prognosis may be. Conservative treatment sounds like the right way to go. Your veterinarians are absolutely right in advising you to give her six more months turned out before thinking about putting her back in work, and I'm sure they're going to want to reassess her soundness level at that point before they clear her for even light work. I agree, pasture sound is a good goal to work towards, and it is difficult for any of us to say how sound she will be or how long it will take to get there.
6
Question: I own a 10-year-old Quarab gelding that presents swelling at the top of the rear pastern, but shows no lameness. The swelling has shown no improvement after two weeks of home treatment. My veterinarian does not own a portable radiograph or clinic radiograph machine for horses. I need to haul him. Should I go direct to the University vet school, or a veterinarian at almost half the distance that has imaging equipment, but is not an "equine hospital"? Or should I give it more time and continue with the home treatment? He was not "in work" when the injury occurred and his job is mostly a pasture ornament with very little trail work.
Answer: 
I'll do my best to answer this question with the limited information given. First of all, is the swelling hard or soft? This will help you and your veterinarian to decide whether it would be better to take xrays first, or to ultrasound it first, although the information that the horse is sound makes me lean towards ultrasound as the first choice for diagnostics, since it is rare for a horse with a bony abnormality to be sound, although it is possible. This is why it is difficult if not impossible to answer these questions without seeing the patient. Is the swelling hot or warm, and is it painful on palpation? Was there any trauma observed that caused the injury, like a kick from another horse, a bad step or trip, or playing rough with pasture buddies? This will help you to decide how recent and how severe the injury is. Frequently, we wait at least three to five days after injury to perform an ultrasonographic exam, as this allows time for the surrounding soft tissue swelling to go down, which lets us get a better view of the structures we're trying to assess. What is the "home treatment" that the horse is getting? There are many options for this, including stall rest and/or handwalking, treatment with nonsteroidal anti-inflammatories such as bute or banamine, cold therapy, and poulticing or other types of wraps and pressure bandages. Has the horse shown any improvement at all after the home treatment? How far of a drive is it to the nearest university vet school, and how far is it to the local clinic? Does the local clinic concentrate on horses even though they are not an equine hospital, as you reported, and are you comfortable with the level of care that your horse would get there? Finally, you must decide what your goals are for this horse and how rapidly you want to achieve them, and to this end how much money and time you are willing to spend. If the horse is sound and comfortable, and you are satisfied to keep him at home and take the "wait and see" approach, if advised by your veterinarian that that is an acceptable option, than certainly do that. If you would rather try to get an answer as to what is causing the swelling and how best to resolve it, then you may want to consider shipping the horse to a facility that can help you get these answers. There are many options for dealing with swellings such as these, and the most important thing to consider first is the health and safety of the horse - above all, we want to make sure that we're not dealing with an injury that may get worse if it is not treated properly. Your veterinarian can discuss with you what is the best option for you and your horse.
7
Question: I have a 13-year-old, 14.2 hand pony on rehabilitation following a tear in her left hind annular ligament (fetlock area) during August. She was only ever lame at a trot. She has recovered very well and has been on walk road exercise for one month and some trot work for two weeks. We are just starting to introduce a little canter work. She is still on box stall rest to avoid injury in the field but I am hoping to get her out during the day anytime soon. Are there any specific exercises that would benefit her return to jumping and anything to avoid?
Answer: 
With any type of soft tissue injury, slow and steady return to work is the key. As you've probably discussed with your veterinarian, your pony should not be turned out in a big field where she can re-injure herself until she's almost back to full work. You can talk to your veterinarian about possibly turning her out in a small paddock or round pen, especially if she's quiet and doesn't usually run or play much, to get a little more exercise in a somewhat controlled setting. You probably started the trot work on the straightaways and gradually added turns, and tried to keep her on a firmer surface and out of any deep footing or sand, which would put more strain on her tendons, ligaments, and other soft tissue. I often advise owners to add either one minute of trot work per day, or five minutes per week, so you gradually work up to thirty minutes of trot work per session, and begin canter work when you have reached thirty minutes of trot work. Avoid sharp turns, especially at higher speeds. It's a tedious process, but necessary to allow the structures to heal while reducing the risk of re-injury.
8
Question: Are there any supplements that can help with rehabilitation? We have tried homeopathy and different types of physiotherapy, which have worked, but maybe there could be supplements, (except C and collagen, and devil's claw) that could help during the first weeks?
Answer: 
There are many supplements available that are intended to support tendon and ligament health. As you noted, antioxidants like vitamin C and vitamin E are important, as well as collagen and other building blocks such as MSM. Amino acids, L-carnitine, and creatine may help support muscle function, which may take some of the strain off of other soft tissue structures. Hyaluronin, polyglycan, glucosamine, and chondroitin may help support joint health. There are also Chinese herbal supplements available to support certain tissues within the body, including tendons and ligaments. As with any dietary supplement, these are not a substitute for a good feeding program, and they should not be used as a substitute for veterinary care, but rather used in conjunction with regular visits from your veterinarian they can help support a program that addresses your horse's needs. Consult your veterinarian and remember that supplements are not proven to treat any conditions, but may be part of a protocol that ultimately benefits your horse.
9
Question: With a suspensory injury, does the lesion ever fill in or look normal on ultrasound after rehabilitation? What are the chances of re-injury?
Answer: 
Both of these are excellent questions, and unfortunately both vary depending on the individual case. It is possible for a suspensory lesion to fill in, given enough time, but sometimes they persist on ultrasound even a year or more after the original injury. Certain therapies, such as the injection of PRP, can cause a lesion to fill in ultrasonographically, although the ligament may still not be as strong as it was prior to the injury. Sometimes the lesion may fill in with slightly different tissue fibers, which causes it to remain visible on ultrasound. In certain cases, the ligament may contain muscle fibers interspersed throughout the structure, which may make interpretation of the ultrasound difficult, both before and after injury and rest and rehab time. This is more commonly found in hind suspensory ligaments. The potential for re-injury depends on many factors, such as severity of the injury, therapies used during rehabilitation, length of time before return to full athletic function, and intensity of training.
10
Question: I have a 14-year-old Quarter horse gelding that I use for English flat and western pleasure along with horsemanship lessons and show him. He came up lame on his right front beginning last January. Radiographs showed he had bone chips in front of his fetlock joint, which we thought needed to be removed. After diagnostics, the veterinarian did not feel the bone fragments were the problem. The MRI showed soft tissue damage including the ligament that attaches to the coffin joint was enlarged three times it's usual size and there was swelling of the navicular bursa. To date, he has had radiographs, ultrasound and a MRI. The fetlock joint was injected and the navicular bursa and coffin joint were also injected with no results. We have tried stall rest, and bar shoes neither of which have worked. Any suggestions?
Answer: 
As you have found, this can be a very frustrating problem, and yours is complicated by the fact that there were bone chips found on x-ray. It is not uncommon to find bone chips in the fetlock joint that are occurring coincidentally and are not actually the problem, which is sometimes disappointing because the owner and the veterinarian both want to be able to remove the chips and solve the problem, but the chips are not the cause of the lameness, so the search must continue. There are many small but important structures in the foot that can often be the cause of the problem, and I'm glad that you and your veterinarian pursued so many imaging modalities to get a good idea of what the actual cause of the lameness is. You're probably talking about either the impar ligament of the navicular bone, the medial collateral ligament of the coffin bone, or the collateral ligament of the coffin bone - in any case, as you have found, these structures are difficult to image without MRI and just as difficult to treat, since they are, to some extent, enclosed within the hoof capsule. They are also, unfortunately, slow to heal in most cases. Stall rest, bar shoes, and NSAID (bute, etc.) treatment are all good therapies for this type of injury. Your veterinarian may also want to suggest extracorporeal shock wave therapy, and possibly therapeutic shoeing to raise the horse's heels. In severe cases where further degeneration is less of a concern, a last ditch treatment may be to cut the palmar digital nerves ("nerving"), but this should only be done when all other treatment methods have been exhausted because of the potential for complications.
11
Question: My 18-year-old horse tore 60% of his deep flexor tendon. We are five months into recovery. Will he ever be able to jump again or do these injuries have a tendency to tear again?
Answer: 
This is an excellent question and one I often get from my clients. Unfortunately, each case is individual and there is no way to predict which injuries will recur and which will not. It is widely accepted that stall rest, "active rest", and a slow return to work are all very important in cases like this. The larger the lesion, the worse the prognosis is and the more likely the horse will re-injure the tendon when he resumes work. Front limb injuries have a better prognosis than hind limb injuries, but adding extracorporeal shock wave therapy during the rehabilitation period may improve the prognosis in hind limb injuries. Traditional support bandages like polo wraps don't actually help support the tendons during exercise, but there are new support boots on the market that may in fact help support the tendons during and after the rehab period, which could help prevent re-injury. These cases can sometimes be "heartbreakers", because it is possible to give the horse all the time he needs, bring him back to work very gradually, and still experience a re-injury, despite taking all possible precautions.
12
Question: My horse currently has swelling on the outside of her carpal joint and advanced arthritis in the radiocarpal joint. The swelling was diagnosed as 'Carpal Tunnel Syndrome,' and following a scan, the Superficial ligament was thought to be the problem. The swelling frequently comes and goes and my horse is only walked out a couple of times a week - any schooling results in noticeable lameness. On light work, the veterinarian confirms she is sound (she was rested for 7 months and is on monthly injections of Carprofen). My question is what are your experiences of Carpal Tunnel in horses and is this frequently seen in horses with arthritic changes in the joint?
Answer: 
You're probably referring to an accumulation of fluid within your mare's carpal canal, which is a structure that surrounds the superficial and deep digital flexor tendons at the area of the horse's carpus, or knee. There are many potential causes of this swelling, but unfortunately without viewing your mare's radiographs and ultrasound images, it's impossible to say exactly what is the cause here. In her case, it sounds like she has two potential issues: her arthritic changes, and the 'problem' with her superficial digital flexor tendon. Either one of these issues may cause lameness on their own, as well as causing fluid to build up within the carpal canal, which could potentially contribute to her lameness. Your veterinarian will be best able to determine which is the most likely cause of the accumulation of fluid, and how best to address it. Arthritic changes are usually changes on the articular surfaces of bones, which would be treated differently from tendon damage, since in general mild arthritis is treated with mild to moderate amounts of exercise, while horses with tendon or ligament damage are frequently rested. Carprofen is one non-steroidal anti-inflammatory drug used to treat pain and inflammation caused by arthritis and/or tendon and ligament damage. Another commonly used anti-inflammatory is phenylbutazone, or "bute". Your veterinarian may also recommend injecting the carpal canal with hyaluronic acid and/or corticosteroids, which can often alleviate joint effusion and the inflammation that causes it.

Ask the vet: Infectious disease

The summer may be drawing to a close, but the threat of Infectious Disease still lingers. Make sure your horse(s) is still safe. Pose your infectious disease questions to this month's AAEP expert, Dr. Phoebe Smith.

1
Question: Can a horse that has had Potomac Horse Fever (PHF) make a complete recovery? Can they return to their prior job as if nothing has happened or will their performance ability be diminished?
Answer: 
Yes, a horse can recover completely from Potomac Horse Fever (PHF) and return to normal performance. Not all horses do recover to this degree. The severity of clinical signs is quite wide with PHF, and the development and severity of laminitis is often the limiting factor in future athletic endeavors.
2
Question: I have a 19-year-old gelding and a recently acquired 11-year-old mare. I've had the mare for about three months. Three times since I've owned her, I have noticed that she has episodes of short rapid 'puffy' breaths, no nasal drainage and no sweating. Just over the past couple weeks, I have now noticed that my gelding (I have had him since he was a foal) has had the same 'episodes' on about 3 or 4 occasions! The rapid breathing goes away in about 3-4 hours. They receive very little sweet feed (about 2 cups) morning and night and are locked in for the night at 8 pm. I let them out again to graze around 2 pm daily. I've had horses over the years in this same pasture and have never had any problems but am wondering if it is some kind of a new weed growing (we have a 5-way grass mixture) or if I need to be concerned about illness.
Answer: 
The episodes of rapid breathing sound very curious. Unfortunately, without seeing/touching/listening to your horses, I cannot offer much useful information. I'd recommend your veterinarian examine both horses as a starting point. Lab work and an assessment of your pastures may also be useful.
3
Question: I have a beautiful Palomino Quarter horse gelding that I want to show. When I got him last year, they told me not to vaccinate him because he foundered two days after his last routine vaccines. That was back in 2008. He was in the same barn so it was not a problem. Now I own him and the barn that I want to go to, won't let me board him without a flu/rhino vaccine. His previous veterinarian said no...don't vaccinate him as it's not worth the risk. Do you have any suggestions for me? Is there a vaccine that pinpoints herpes? Is there a more mild, for lack of a better word, type of vaccine that I could give? I don't want to risk my horse's life, but just thinking there must be someway to protect horses that have adverse reactions.
Answer: 
This is a very difficult, if not impossible, question to answer. My best advice is to request the specific vaccine type (manufacturer, vaccine trade name) from your horse's previous veterinarian. The previous owner may need to authorize your acquisition of this information. Then discuss with your current veterinarian the options available for vaccination with different products. Each manufacturer uses a different adjuvent (a substance that is added to the vaccine to increase the body's immune response to the vaccine). There are multiple vaccines available targeting herpes virus, both in combination with flu and alone. Ultimately, you and your regular veterinarian are best suited to determine the best preventive care program and living environment for your horse. I apologize that I cannot answer your question more specifically.
4
Question: My 13-year-old pony mare recently showed part of the symptoms of strangles. She had a moderately high temperature and swollen lymph nodes on both sides of the jaw as well as between the lower jaw. I called my veterinarian, but as he was very busy and my pony didn't show any nasal discharge, he told me to wait. The next day, the temperature had gone back to normal and in three (3) days the swelling had decreased without any medication and disappeared in about a week. The mare never lost her appetite yet the lymph nodes were obviously painful when palpated. The other horse, a 15-year-old gelding, never showed any symptoms. My two horses never go out of their pasture and never mix with other horses. Do you think it was benign strangles or could it be something else? Thank you in advance for your answer.
Answer: 
Strangles can cause less severe disease in adult horses than in younger horses, such as the clinical signs you describe. Strangles can also lie dormant in "silent carriers" and cause disease in unprotected and incompletely protected horses. So it is possible that your pony mare indeed had strangles. Additionally, horses can be exposed to the strangles bacteria through contaminated clothing and equipment (called fomites) and develop illness, so direct contact with a sick horse is not required for the development of disease. However, it seems more likely that your mare had another disease causing her short-lived fever and lymph node swelling. We really can't be sure on this one.
5
Question: It's the end of summer and in the 90's with unusual humidity for California. To my frustration, my gelding has presented a fever of 104+/- and a snotty nose. My veterinarian suspects a virus. This horse has been on "bed" rest for the last month due to lameness. How the heck did he contact a virus with no other horses on the property or within nose contact?
Answer: 
Fever and nasal discharge may indeed be caused by viral infection, or by bacterial infection. Equine herpes virus lies dormant in clinically healthy horses until periods of stress, when it becomes re-activated, causing clinical disease. Another possibility in this case is that transmission occurred between a contaminated item, or even person, and your horse. In the early stages of viral infection, there may be no outward signs and thus transmission can occur by fomite (person or item) quite readily. Additionally, it can be difficult to distinguish viral from bacterial infections in the first few days of clinical disease. Viral infections typically resolve within a few days, while bacterial infections are often more prolonged.

Ask the vet: Summer Eczema/ Summer Itch.

Is your horse feeling itchy? Maybe it's the season . . . Join us in AugustAAEP expert, Dr. Frank Reilly, answers your questions concerning your horse's summer itches.

1
Question: I have a Clydesdale mare with sweet itch. This spring and summer I was able to keep the itching at bay for the most part with heavy, twice a day, Permethrin spray. In the summer, she goes out at night because she stays in during the day to avoid the Texas heat. However, these past two weeks, she has come in with evidence of scratching her face and neck a lot, which seems like a reaction to something else besides culicoides. It is hot and dry in Texas in August and not favorable for culicoides breeding. Is it another insect allergy or could she be allergic to something else? I suspect she also has other allergies. What types of food allergies can horses have? Is it effective to give a corticosteroid shot in the spring at the first sign of itching, as well as periodic shots instead of daily steroid? I'm aware of the side effects but I'm wondering if the benefit of giving the lowest possible dose to control the itching cascade would outweigh the risks.

I read your recommendations about baths, sprays and herbal supplements. What is the best herbal anti-inflammatory combination?
Answer: 
Culicoides bite at night, so when you are having problems at night, it is likely them.Yes, many folks have to do night turnout due to heat. Also, there are over 20 species of culicoides, that said, your horse can be allergic to many different species and one of them might have moved in recently or had a population explosion and is overwhelming the skin. 


You need to apply strong spray on a paper towel and wipe the face, ears and neck. Also, make sure your spray is high in piperonyl as this allows pythrerins/permethrin to work better.


I would add omega 3's to her diet to help the skin. Also, search or Google "equine summer eczema herbals" for natural oral formulas  to help her skin as there are many choices.
2
Question: My 15-year-old Morab palomino has developed a terrible hypersensitivity to both vaccines and now the bugs (and even some weeds) of spring and summer and has had terrible outbreaks of hives! At present, he is on a daily dose of 5 Hydroxizine tabs AM/PM after initial loading doses to get the reaction down. Recently, he has become lethargic and, while his coat is incredibly golden (having been covered all summer), his gums are pale and his mane and tail are slowly falling out. He is on an Omega supplement and, while I know it helps, I cannot seem to get him over this slump. Blood was drawn and he is only mildly anemic. The veterinarian thinks he may have developed a selenium toxicity because of the mane and tail hair loss symptom, which started about 3 weeks ago. I have tried to come up with a number for the selenium content in his feed and it may be around 3.5 mg - feed and supplements considered - and we are in Northern Illinois. While this seems high to me, I have read that 5 mg is the high end for this area. He is so uncomfortable, and now with the suggestion of a possible selenium toxicity - I don't know what to do and how to treat him. I have eliminated all possible sources of selenium except the omega supplement as of this week - that sel. value is .8 - and it helps with the itchiness. This is a terrible summer for bugs!
Answer: 
You are describing several allergy events in your Morab. Allergic reactions to insects, usually culicoides, resulting in equine summer eczema (itching, skin crusts, rubbing, hair loss...) AND food allergy to weeds resulting in hives. Horses that are hyper-reactive to these (one or both), often are more reactive to vaccines. At vaccine time, split up into 3 sessions 1 week apart (so less antigen load) and 2 hours prior to administering the vaccines, give banamine and pyrilamine in the vein. By having these medications on board, prior to vaccination, really helps. Also, avoid giving vaccines in the neck. Instead, use that big gluteal on the hind end.

Next, the insects. You need to treat this condition using a strong fly spray 2x a day (culicoides eat at dusk to dawn but regular flies attack damaged skin in morning) at dusk and morning. He also should be bathed 3x a week to remove urine attraction (culicoides are 30x more attracted to horse urine than cattle urine). Oral herbs can also be given daily to lessen reactions. Your omega supplement is helpful due to omega 3's, which help skin quality, but it's not going to be able to stand alone. Your horse needs a barrier system (spray) and also consider night stalling with 2 fans to blow away culicoides since they are weak fliers. Your mane and tail hair loss is very common in equine summer eczema.

Selenium toxicity is rare and Illinois, from studies with corn, show that area is actually low in selenium. Yes, 5mg is the top level. I would run a selenium blood level test (do not use sst tubes with gel as these create false low numbers due to selenium trapped in gel) and submit the spun down serum on ice packs to New Boltons Toxicology Lab(610-444-5800). The lab can tell you blood levels for peace of mind, but I bet they are fine. Your Omega supplement is fine and not a large selenium source. Remember, on your feed label, for example, if its 2ppm selenium, that means 2 mg selenium for every 2.2 pounds of feed. If feeding 1 pound of feed, then its about only 1mg selenium.

Your hydroxyzine is a antihistamine but also has side effects of being a tranquilizer and can make your horse drowsy. Your anemia requires your vet to go over your feeding program and double check your deworming program to ensure parasites are not leading to anemia.
3
Question: I have a mare with anhydrous, which I am treating with a product from Platinum with success, but I am still dealing with a dry coat and itching. I use a coat conditioning supplement in her feed but still have to deal with this issue. Any suggestions?
Answer: 
The Refresh product from Platinum is electrolytes, vitamins and amino acids, so the addition of omega-3's are ok to add for added coat condition. Including a 1/4 cup of ground flax seed, once a day, for a 1000-pound horse is helpful. Poor coats also can be from parasites. Go over your deworming schedule  with your veterinarian to ensure you are not leaning too heavy on fecal tests, which miss tapeworms, bots and encysted strongyles. Also, the addition of a ration balancer with about 30% protein helps skin, which is mostly protein.
4
Question: My 6-year-old Morab mare has evidenced allergic dermatitis the two summers that I have owned her. She was given initial dexamethazone injections and then daily prednisone tablets. I also shampoo her with EquiShield shampoo, spray with Genesis spray and fly spray and give Wellactin omega-3 oil. She is better, but not cured. We are considering having CSU vets do immunotherapy after fly season and after she is off steroids. Is there any reason to be optimistic that immunotherapy will cure her?
Answer: 
For certain conditons, immunotherapy can work (i.e. stems cells into injured tissue), but for allergy issues, it is difficult to say allergy shots are effective most of the time (and there is the expense). For example, culicoide (#1 cause of allergic skin itching in horses) gnats come in over 20 species. Your horse will be tested for 1-2 of those, but could have problems with 5 out of 20 for example. Often, horses are ok until the population of the allergic gnat overwhelms the immune system. You have many good points in your program:


1. Baths--horse urine is 30x more attractive to these gnats than cattle urine. Bathe your horse three times a week, as once a week will not work. Any shampoo works well, even dawn dish soap.


2. Omega-3--wellactin and fish oil are great, but add flax to the mix (highest omega-3 product in world as well as economical). Take 1/4 cup flax seed, grind in coffee grinder (K-mart has them for about $15) and feed once a day. Flax seed must be ground to be effective.


3. Genesis spray (topical steroid spray) + dexamethasone shots + prednisone tablets all are used to control inflammatory reaction AFTER the bite. This tells you that the barrier system being used is failing. Your spray is not strong enough and its not being used enough. All fly sprays degrade in sunlight and gnats start biting at dusk, so you need to spray twice at day and dusk and morning (morning spray can help stop other pests from attacking damaged skin).


4. Consider flysheets (wash once a week to avoid urine attraction) and night stalling with two fans blowing as culicoides are tiny and weak fliers. Fans and sheets are barriers on top of a better fly spray and more applying of it.


5. Try some of these added management ideas and keep me posted.
5
Question: Through the years, I have had several horses, as well as noted clients horses, that loose mane hair on the underside of the mane. This causes a thinning of the mane. The area is slightly flaky but does not appear red or inflamed. The flakiness is not more than the normal appearing thicker mane. No history of rubbing this area of the neck, and the condition does not appear to bother the horse at all. Any ideas what causes this or if there is a way to encourage mane hair growth in this area once it happens?
Answer: 
Often, when I am not sure of what is causing a skin problem specifically, I will treat the most common skin conditions and get good results; what exactly was the problem goes undiagnosed, but the horse improves.

1. Insect hypersensitivity mild case----2x day spraying of a strong fly spray + omega-3 oil via 1/4 cup flax seed then ground in a coffee grinder (K-mart for $15) +  bathing area 3x a week with any shampoo. I have luck with dawn dish soap + oral herbals that keep inflammation down.

2. Parasites--I will do Equimax paste dewormer three weeks in a row (i.e. Monday, Monday, Monday).

Many horses skin problems are due to deworming schedules too dependent on fecals. Tapeworms, bots, encysted stronglyes can be missed on fecals and a lot not dewormed for 6+ months. By using this program also helps get many ectoparasites. I will have the owner then go every 60 days with dewormers during the season of hair loss.

3. Sunshine increase--many of these horses get mild bacterial/fungal hair problems that sunlight helps control.

4. Nutrition---I will add more protein to the diet. There are many ration balancers with higher protein and zinc to help immune system of skin. Three baking cups is equal to one pound given to a 1000-pound horse. Skin is mostly protein.

5. I figure if I can get the top 3 or 4 causes of skin problems, then I will get most cases- shotgunning some may say, but the above items are easy and economical to try.
6
Question: My horse gets itchy on his sheath. He then scratches it with his teeth, which causes swelling. If I put swat on him every other day it prevents this from happening. Are any of the anti-itch supplements useful? I was concerned because of the ingredients like calf thymus. Other ingredients of some of these supplements included diatamacious earth  as I don't want to give this to my horse.
Answer: 
Your horse has a insect hypersensitivity reaction to most likely culicoides gnat, the #1 cause of itching in horses. There are many thing that can help:

1. Strong fly spray sprayed on the sheath twice a day in dusk (when they come out to bite) and in morning when other flies attack damaged skin. You can spray sheath safely but do not spray directly on the penis. Blast the spray right up the groin, belly area as the spray will cover a larger area than ointment swat and gets way under between the legs better.

2. Bathe your horse three times a week as urine of horses is 30x more attractive these insects than cattle urine. Be sure to scrub the sheath area with medicated shampoo and rinse well. You may use a medicated shampoo for three weeks then after that any shampoo, even dawn dish soap. If you find yourself in a pinch after a ride, at least hose off the sheath area with water and bath next day.

3. Consider night stalling with two fans blowing in the stall as this keep the insects away.

4. Fly sheets are of little help in this area.

5. Consider daily herbal anti-inflammatory therapy.

6. Add omega 3's to the diet including 1/4 cup of ground flax seed (#1 for omega 3 content of any product) or use chia seed (no need to grind) or a daily dose of 30cc orally of wheat germ oil. Purchase 100% Wheat germ oil and not the blend, which is 1/2 corn oil. Some horses may need an iv/im shot of antihistamines/steroids as a one time therapy for quick relief, but keep dose low. If your horse has Cushing's or insulin resistance (IR), your veterinarian will likely use only antihistamines.

7. If area looks infected from wounds, call your veterinarian for antibiotics--if your horse is not dropping out his penis fully and the area is getting sprayed with urine, your veterinarian will sedate the horse and check to see what the problem is. Get your horse's sheath cleaned with clean water every few months if he is one of those horses that accumulate a lot of debris.
7
Question: I have three horses stabled in a barn with a horse that was recently diagnosed with "herpes". His symptoms are lesions on both of his ears and his chest. Their reason for how he contracted the disease was from a fly bite that bit a cow and then bit him. I have two mares and a stallion in this barn and I am worried because this horse has not been isolated and is stalled right next to one of the mares that was scheduled for the breeding shed in the spring. Is this herpes and will my horses be effected?
Answer: 
What you are describing is a sarcoid, which will cause small benign tumors on the skin. Some will be nodular, some will be rough like sandpape and some will be in pinhead-like bumps. This problem appears from the latest research to be most likely from a form of papilloma virus very similar to that of cow papilloma. A papilloma virus is a different class than the herpes virus, therefore; your breeding should go on and do well. The one drawback of the sarcoid is its ability to topically spread on the skin to other places on that horse, but also when these areas become raw and bloody, spread to other horses. Sarcoids are the most common skin tumor of horses, but are benign, meaning they do not move internally or lead to loss of life. Many horse operations have sarcoid horses in a herd with no resulting transfer to other horses. There are many different treatments for sarcoids and your farm veterinarian can direct you to the ones they have found to be the best for the type this horse has on its chest and ears.
8
Question: I have a mare that cannot stop rubbing. In the past, she has almost rubbed her entire tail off and most of the hair on her hindquarters. I have covered most things so she can't rub her tail off. She chews on her legs a lot. I keep fly spray on the best I can and have a barn fan in the shed where she spends nights. I know she is miserable, but is there anything else I can do? My other horses are not as bothered.
Answer: 
Yes, your horse has an insect hypersensitivity allergy, so other horses are fine but she is likel unhappy.

Please go to my other responses to see program---your fans at night are great but make sure at least two of them are blowing so there is a great deal of turbulence as culicoides are tiny and have a hard time traveling through these conditions.

You also need to spray twice with a strong fly spray(doing right on tail but also entire body and up groin also), a good deworming program, include omega 3's within her current diet, if bathing, she will need to be bathed three times a week to remove attraction, possible herbal anti-inflammatories added. Unfortunately, no one thing will stop it and will require a gang tackling to get results. I like using a medicated shampoo for 30 days then go to any shampoo, even dawn dish soap, works well.
9
Question: I purchased a Tennessee Walking horse (light bay) this May. He had just a little dandruff in his mane, but it cleared up. Now he has lost two long chunks of his mane from scratching. In among the roots of the hairs are small red areas and some light scabbing. He also has flaking at the top area of his mane. I am currently giving him a top-dressing bug-off additive and it seems to be working for most of his body, but he has rubbed his chest area and now has small raw areas. I have tried horse products for itchiness, but many of them had sulfur and he welted from them. Head and Shoulders for itchy scalps seems to be working for the mane and tail issues if I use it every day. I am putting an ointment on his chest to help it heal and to keep small insects away. I use Ultrashield on his body and legs where there doesn't seem to be a problem. Also, he has managed to scratch both sides of his sheath with his hooves, so that there are raw spots there as well. I am using the ointment there as well. He goes out at 4am and comes in at 10:30am as the Florida heat is terrible right now and he likes the stall fans, which probably help keep the bugs at bay. I am at my wits end trying to make him comfortable.
Answer: 
Have your veterinarian look over chunks of hair area as this might be a combination of rain rot (hair out in paint brushs like chunks with bacterial pus under) and insect hypersensitivity.Your doctor may need to put your horse on antibiotics for a small time.Your shampooing is a great idea since the culicoides are very attracted to urine, but you must bath 3x a week at a minimum. Currently, in an outbreak, you are using a medicated shampoo, which is perfect, as you need to avoid secondary bacterial infections from bites or from horse self mutilating skin from rubbing on posts, kicking himself with back feet into his own sheath. Next, your spray is good, but it is not being used correctly if he is kicking his sheath. You can spray these right onto the sheath (not on penis) on both sides. Give him a blast of fly spray twice a day at dusk and in the morning over the entire body including mane. Your spot on will not protect the entire body as it is NOT in the same class of medications as spot on dog products. The horse spot on is only pyrethrins or derivatives of that. Also, add omega 3's to the diet and ensure you are deworming correctly at least every 60 days with these type horses--do not rely on fecal tests--see my last response for dosing omegas and dewormers. Remember culicoides eat at nite, so nite turnout requires daily dusk fly spray over the entire body. However, many horse owners in Florida are doing as you are with nite turnout due to hot daytime and providing a stall he can walk into with fans to blow insects away at nite or a shed with fans in the corners to further avoid culicoides since fly sheets in hot weather are difficult.
10
Question: I have a middle-aged pony that in the summer, particularly July and August, starts to itch. Itching is mainly on her face, neck and chest. Her once beautiful mane becomes very brittle and breaks off as does her forelock and tail. Her tail also begins to look like a honey comb with all the dead skin build up. I have tried the usual shampoos, conditioners sprays, ointment, fly sheets, feed additives, etc. I have not done blood workups on her. Is this something I should try and what tests should be run?
Answer: 
What your pony has is a specific allergy to a specific insect or group of insects that move into your area during this time, OR are there but reproduce rapidly at that time so the numbers are overwhelming. Remember, there are over 20 species of culicoides and the populations change and your horse might not be allergic to one type of culicoides but is to another that moves into that area.

I would suggest several items to "combo- tackle" the problem--1 or 2 things will fail:

1. Make sure you are deworming every 60 days with ivermectin products from May to Sept (i.e., May, July, Sept) as you will need the immune system at peak performance (wormy horses have poor coats and poor protective barriers). 

2. Add omega-3 products shown to help skin in small animals---flax seed (you may have to grind up to 1/4 cup of seeds a day, every day as flax is highest in omegas), or chia seed at 1/8th of a cup a day (no grinding) or wheat germ oil at 30cc a day (NOT wheat germ oil blend which is 1/2 corn oil--get 100% wheat germ oil).

3. Sprays---2x day at dusk and in morning--use with pyrethrins, permethrin,  piperonyl stabilizer. No fly spray lasts over 12 hrs as sunlight breaks them down. Be sure to pay attention and spray on mane and spray a clean paper towel with two pumps and wipe her face. It is very important to know that often spray is weak or not applied at right times or not done twice a day. Why should you spray during the day? Damaged skin attracts other flies.


4.Oral herbals with anti-inflammatory ability can help.



5.Yes, shampoos can help but must be done 3x a week for effect since the urine of horses is very attractive to culicoides (30x more then cattle urine). Also, blankets that get dirt/urine on them can be a problem as they need to be cleaned once a week or put a new one on.

6. Stall at night with fans as culicoides are tiny and poor fliers and eat at dusk to dawn.
11
Question: I recently purchased a 13-year-old Tennessee Walking horse that was on 24-hour turnout. Now he has a stall and is turned out 7-10 hours per day. He has managed to scratch out part of his long mane (on trees, walls,etc.) When I look between the hair roots of his missing mane area is it red and slightly scabby. Also, along the opposite side of his neck where his mane originates, there are faintly bumpy areas where there are dead skin flakes (gray in color) that are rising from his skin's surface. I am using a very very fine toothed comb to remove these flakes and separate them from his coat. There is no loss of hair, just these flakes rising from his skin's surface. I am at a loss as what to do for him. His tail, at the base, has also flaked before, but I have gotten this under control using Micro-Tek spray, however, it doesn't seem to be working for his mane area....HELP!!!!!
Answer: 
The most common allergic condition of the horse is insect hypersensitivity and the #1 cause of that is allergic reaction to the bite of culicoides---this can produce an itch that has your horse self-mutilating its skin via vigorous rubbing on fences, poles, trees like you are seeing. There are several steps to take to help your horse:

1. Apply a strong fly spray 2x a day---culicoides bite from dusk to dawn so apply once at dusk, but also in morning---damaged skin is attractive to other bugs during the day.

2. Bathe 3x week--the urine of the horse is very attractive to culicoides--when they roll, they place urinary components into the mane. The baths also soothe damaged skin by preventing secondary infections.

3. Add omega 3 to diet via flax seed (ground), chia seed or wheat germ oil--shown to help soothe skin.

4.Go over your deworming program with your veterinarian----ensure onchocerca is not an issue--ivermectins also can be of help in lice, mite problems (given multiple times over weeks).

5. Nite time stalling with fans would help avoid culicoides due to weak fliers and eat at nite. Remove any old standing water that breed culicoides (tires with water in them, stagnant water). Please remember that these insects can fly up to one mile, therefore; if your neighbors have standing water, it will be tough to stop.

6.Fly sheets may also benefit--- another barrier on top of fly spray, to protect--are ones that cover the mane.

7.Your veterinarian also can do a skin scraping of the area.
12
Question: The use of cortocosteroids (oral prednisolone or injectable Vetalog) are invariably recommended by my veterinarian to treat sweet itch in my 20-year-old mare with worsening symptoms each season. Which horses will develop laminitis in response to steroid therapy? Is the horse more at risk of doing so each subsequent year? How can the risk be reduced?
Answer: 
At times, in severe outbreaks of summer eczema, steroids may be needed for one to two treatments to decrease inflammation and stop itching that is so bad the horse mutilates itself by rubbing on fence posts or crawling on the ground, rubbing its belly over rocks. Steroids for this small amount of time avoid problems with possible triggering of insulin resistance surging or laminitis episodes in horses with Isulin Resistance (IR) and Cushing's. Long term, daily steroids are not an option in horses with IR, Cushing's, past laminitis and studies have shown even in normal horses, IR can be seen in long-term steroid use over 21 days. The goal is to avoid the active case by management---fans blow culicoides away easily as they begin biting at dusk to dawn. That said, stalling at nite with fans helps. The 2x day application of strong fly sprays is mandatory to avoid the bites. The addition of omega-3 supplements such as flax seed (ground), chia seed or wheat germ oil has been shown to help skin conditions and skin health. Baths given 3x a week has been shown to be very helpful in reducing bites as the horse's urine is very attractive to these insects. Barriers of fly sheets can help, but they must be cleaned regularly of horse urine picked up when they roll. The use of daily antihistamines has been used, but like steroids, this is only treating the horse after its bitten, which is not the goal.

Ask the vet: Nutrition

Join AAEP's "Ask the Vet" forum during July to pose your questions on the topic of equine nutrition to our AAEP expert, Dr. Lydia Gray from SmartPak Equine.

1
Question: In the hot summer months when my horses are sweating a lot, which electrolyte supplement would you recommend feeding? There are so many on the market and so many articles about which ones to feed and which ones to avoid.
Answer: 
I agree, there are a lot of choices out there when it comes to electrolytes! And since replacing the vital nutrients lost in sweat as well as encouraging horses to drink and rehydrate themselves are both critical to your horses’ health, so let’s see if we can help you sort things out. 

Some things to consider when choosing an electrolyte are palatability (i.e. tastiness), the presence of extra or unnecessary ingredients (like sugar), and how closely the supplement mimics the minerals horses lose in their sweat. The ideal equine electrolyte, therefore would be one that horses eat readily, that contains little or no added sugar, and that is formulated to replace what is actually lost from the horse due to sweating. Numerous studies in this area have shown that the major ions found in horse sweat are chloride (Cl), sodium (Na), and potassium (K), in that order, with a little bit of calcium (Ca), so look for a supplement with primarily these macrominerals. Here is a link to a fact sheet with more detail about sweating in horses and electrolyte supplementation to replenish losses: http://www.thehorse.com/free-reports/30000/electrolytes. 
2
Question: I would like to know, when feeding crimped oats, what vitamin/mineral supplement would be a good choice. My horse is a pleasure AQHA gelding, not worked but 2 to 3 times a week.
Answer: 
If your horse was getting a full serving of a fortified grain I would tell you that a vitamin/mineral supplement isn't necessary, but since your horse is getting just crimped oats for extra calories, you’re smart for looking into a vitamin/mineral supplement to complement his diet. I’m going to assume that he is also getting an appropriate amount of quality hay. 

When looking for a multivitamin, remember that not every horse’s nutrient needs are equal. Your horse’s workload will influence his vitamin and mineral requirements, so look for one that differentiates between different workloads. Also consider looking for a multivitamin designed for his life stage. For example, senior horses may benefit from additional vitamins that also serve as antioxidants such as vitamins E and C. If your horse is older, look for a multivitamin formulated with the senior in mind. Lastly, palatability is important as the supplement won’t do him any good if he doesn't eat it. Try and find a pelleted option, as most horses prefer them to powdered supplements.
3
Question: I have three older horses(15, 20, and 25) that are fed hay twice daily, and get pasture turnout two hours in the afternoon/evening. The pasture is now dry and getting sparse. Their weight remains good as I have always fed 1/2 grass hay and 1/2 oat hay. This year my local feed store has run out of oat hay several times and they recommended feeding wheat hay. I tried it and the horses loved it! Are there any problems associated with feeding non-bearded wheat hay? Any benefits over oat hay?
Answer: 
That’s great that your horses all like the wheat hay, as some don’t care for it. Where I’m located, neither oat nor wheat hay are very common forages for horses; we’re more familiar with oat and wheat straw for bedding. If the wheat hay is beardless, it’s been tested for nitrates, which can be high in both these crops, and you’re feeding a ration balancer to provide protein, vitamins and minerals (especially calcium) then gradually introducing your horses to this new forage should not be an issue. 

If you’re concerned about this significant switch in hay types, consider adding a digestive supplement with ingredients like yeast, probiotics, prebiotics and enzymes to assist in the transition, much as you would when introducing horses to pasture in the spring. Remember that changes in hay can increase a horse’s risk for colic by ten times (while changes in grain can increase the risk five times).
4
Question: I have a 26-year-old Tennessee Walking horse that has recently started losing some weight around his flanks. He is free of parasites (this was checked last month) and an equine dentist pronounced his teeth in good condition. Good pasture is available to him 24/7 and he is also fed about 4lbs of grass hay daily at this time though he prefers to graze in his pasture. He receives no grain. I started him on Purina Senior about 10 days ago to supplement his nutrition needs and am feeding him twice per day (3.5 lbs per feeding). I have been told by my local animal feed store that I could put more weight on him by using Purina Strategy or Purina Ultimum. He is not worked and only on a maintenance feeding plan. He is otherwise alert and seems happy with his other Tennessee Walking horse companion. Could you please advise me on a feeding plan?
Answer: 
Congratulations for getting this far with your guy! Now it may be time to think of him as a senior horse with senior needs. I’m really glad to hear that you've had his mouth inspected and all seems to be fine there. You still need to make sure that he can bite off, chew and swallow pasture grass though and hasn't begun quidding. If you suspect that may be the case, he might not be able to masticate long stem hay either in which case it’s time to transition to chopped hay, hay cubes or hay pellets.

Next, AAEP has just published Parasite Control Guidelines that I would encourage you to read, with one of the first things you’ll learn being that no horse is truly “free” of parasites. He may be a low shedder, or the parasites may not be laying eggs right now, but I’ll guarantee you that your horse has worms so please don’t neglect giving him dewormer at least once or twice a year! The older horse begins to become less efficient in many organ systems, including the immune system, so an appropriate parasite control program (and vaccination program) becomes even more important as he ages.


Another organ system that doesn't work as well as cells and tissues get older is the digestive system. Since he’s now less able to extract nutrition from the same food he’s always eaten, starting him on Purina Equine Senior was a great idea! This commercial “hay and grain in a bag” is specifically made for the older horse, with higher protein levels to keep their topline and other muscles from wasting and easier-to-digest ingredients than traditional concentrate. Since it is like both hay and grain combined--with feeding rates as high as 12, 15, or even 18 pounds per day--don’t be afraid to add a third meal or to give him more each time. Of course, if you switch to a true concentrate like Strategy or Ultium, you would feed much less. So there’s a trade-off between feeding large amounts of a highly digestible feed made for senior horses or smaller amounts of a higher calorie feed made for hardworking or hard-keeping horse. You may want to (gradually) try both approaches and see which does a better job of keeping weight on your individual animal.

There are lots of other ways to put weight on horses and keep it there, and unfortunately you have to do a little bit of experimenting with your own horse to see what works best for him. Some horses really blossom when the diet is supplemented with additional protein or amino acid, others respond to extra fat, while still others gobble down beet pulp, a high fiber feedstuff, which is fermented by the beneficial bacteria in the hindgut into fatty acids or energy. I recommend trying one thing at a time and seeing how your guy does, while at the same time identifying and removing sources of stress or unnecessary calorie loss, such as stomping flies in the summer, shivering in the winter, or illnesses and injuries. I’m also a big proponent of keeping horses in consistent light work as long as possible, soundness permitting, as even walking promotes muscle development.

And of course, stay in touch with your veterinarian, who may want to bump up the annual visit to twice yearly, since problems with immunity, digestion, teeth, hooves and other parts happen much faster once horses enter their golden years. Good luck and enjoy your horses for a long time to come!
5
Question: I have a 10-year-old Warmblood/Thoroughbred that I got last fall. At that time, he was on a high fat high fiber diet. His weight has decreased so we have switched him to a Purina feed, which is suppose to give him all the calories he needs. He has been dewormed recently and does not spill his feed when he eats. I believe his teeth are good. He is currently on grass and always has hay. He shares pasture with two others and is use to being in a herd. I was thinking about checking for ulcers? Any ideas?
Answer: 
If I were your veterinarian trying to help you figure out why your horse lost weight and how he might gain it back, I would want to know a couple more things. For example, what was his body condition score (BCS) last fall when you acquired him and what is it now? Each BCS is about 50 pounds (slightly more for a larger horse like a Warmblood or Draft) so if he was a 5 and is now a 4, he lost 50-75 pounds. If he is a 3 now, he may have lost more like 100-150 pounds.

Next, where do you live and where did the horse come from? If in a northern climate, do you think he either did not acclimate to the move or just in general has a hard time keeping warm in cold weather and burns a lot of calories to do so? I had an OTTB that would consistently lose weight in the SUMMER because he didn’t tolerate the heat or bugs well and just stood around stomping instead of eating. That said, make sure you understand your new horse’s personality and metabolism when it comes to seasonal weather changes.

What do you do with this horse? If he came from a pasture ornament situation into full training and is now expected to compete in dressage, eventing or as a hunter/jumper, then his caloric intake needs to increase accordingly. 

You mention that he is used to being in a herd and now lives with two other horses. How did the establishment of pecking order go? Do you know where he is in herd hierarchy? Sometimes horses get pushed off their hay pile prematurely and spend the bulk of their eating time getting moved around, which uses up calories instead of taking them in. The Warmblood I have now wears a grazing muzzle at all times because he can inhale all eight piles of hay in “his” seven-horse paddock faster than you can say “easy keeper.”

Since you also describe the grain that he eats (Purina TriMAX, available in Canada), I’m assuming you bring your horses into stalls for meals or in some way separate them so they can eat their fair share in peace? Speaking of “fair share,” Purina recommends feeding a range of 0.5 to 0.75kg grain per 100kg body weight. If we assume your horse weighs 500kg (1100lb) then he should be getting 2.5 to 3.75kg each day (5.5 to 8.25lb), aiming for the lower end of the range to meet his minimum vitamin, mineral, and protein needs and the higher end of the range to provide extra calories for heavy work or weight gain. Remember the rule of thumb: no more than 0.5% of a horse’s body weight per grain meal, which for a 500kg (1100lb) horse is 2.5kg (5.5lb). To use this grain as it is intended then, you should be giving your horse 1.875kg (a little over 4lb) in the morning and in the evening.

Since that’s a lot of grain and feeding large amounts of grain has been linked to gastric ulcers, you may want to provide calories via another route, such as beet pulp, alfalfa cubes, a fat supplement or other option. Each horse responds differently to these various methods of increasing the energy in the diet so I recommend trying one at a time, for about a month, before moving on to the next. The clinical signs of ulcers, their diagnosis, treatment and prevention have been covered in great detail elsewhere http://blog.smartpakequine.com/2013/06/foregut-or-hindgut-thats-the-question-part-1/, so I’ll let you research those facts on your own!

Finally, if you have not had a qualified person actually examine his mouth and inspect his teeth since you purchased him (and performance horses usually get looked at twice a year) then it’s time. Also, I strongly urge you to read AAEP’s guidelines on parasite control, to make sure your program is as up-to-date as possible. If careful consideration of what changed in his life since you purchased him and attention to the details of his diet don’t improve things, then it may be time to have your vet out again to examine him and try to get to the bottom of his weight woes.
6
Question: I rescued three starved horses, two 12-year-old Percheron geldings and a 23-year-old Quarter horse mare. My veterinarian told me to put them on some high fat/high fiber and I was also told senior would be the best as its HF-HF, and easily digestible. What would you recommend?
Answer: 
I’m impressed that you rescued three horses at one time! You’ve certainly got your hands full! Fortunately for you, and for them, my background is in horse rescue and I swore by the research that Dr. Carolyn Stull and her team did at the University of California-Davis. She found that starved horses were not unlike starved people (think POWs) in being susceptible to refeeding syndrome, which can be fatal. 

This syndrome happens when a person or animal goes without food for a long time, begins to breakdown their own body for nutrition, then is “rescued” and given food high in energy/calories, which then leads to electrolyte disturbances and even death. She found that small, frequent meals of alfalfa hay were the best way to bring starved horses back to health, as oat hay was too high in fiber and too low in other nutrients but grain was too concentrated a source of calories. Here is the research if you would like to share it with your veterinarian so you can develop a safe feeding plan: http://www.vetmed.ucdavis.edu/vetext/local-assets/pdfs/pdfs_animal_welfare/eq-isoenergetic-javma212-5-691.pdf

My advice is don’t be in a hurry to fatten them up or to put their preventive care programs in order (vaccines, parasites, teeth, hooves). All of these procedures create stress and some, like immunizing, rely on the horse’s body to mount an appropriate response. If they’re truly a body condition score of 1, immunizations will likely slow down their recovery while conferring no protection. So give them time to eat and heal from the inside out; there will be plenty of time later to start providing good veterinary medical care!
7
Question: I own a 13-year-old Morab mare that is out on pasture. I have not been riding much lately. She has her deworming, vaccinations, feet and teeth up to date. Should I give her any free choice mineral, and if so, what would you recommend? The horses do have access to a cobalt salt lick.
Answer: 
There are a couple of key pieces of information missing from your question in order for me to give you the best advice, such as what part of the country you live in, how much and what quality of pasture she has access to, and if she is a an easy keeper or at an ideal weight (she could be a hard keeper but guessing from her breeds that is less likely). Depending on the answers to these questions, your horse “may” be getting a complete and balanced diet just from the pasture, but most horses don’t, as—you got it—minerals can sometimes be lacking or in the wrong ratio in some areas. 

I’m not a big fan of licks for horses, whether they’re white salt licks, red trace mineral licks or blue cobalt licks. These blocks were made for the rougher tongues of cattle and while some horses don’t mind licking them, others scrape them with their teeth or don’t bother with them at all. So loose minerals as you suggest would be a better choice, but rather than asking her to select what she needs or doesn't need (horses don’t have a craving for anything but sodium) why not top-dress salt or minerals onto something she likes, like a handful of oats, hay pellets or beet pulp? By separating the horses just once a day to supply their individual minerals, you’ll be ensuring that each horse gets his or her daily serving of essential nutrients.
8
Question: For a few years, my 18-year-old Appaloosa gelding has been given Equinyl Combo once a day. He has had no serious joint issues, but we want to maintain joint health. A veterinarian recently recommended Cosequin ASU instead. What is your opinion on the efficacy of each? One concern is that Equinyl is partially continued release, and Cosequin is not.
Answer: 
Kudos to you for staying on top of your horse’s joint health! Fortunately, more and more research is being published about the effect of oral supplements on the health of equine joints. ASU or Avocado Soybean Unsaponifiables is one example. In 2007, researchers at Colorado State University gave six grams of ASU (about three times as much as is in Cosequin ASU) to half of the horses in their study and a placebo to the other half. While there was no difference in pain or lameness between the two groups, the horses that received ASU showed a significant reduction in severity of articular cartilage erosion and synovial hemorrhage and a significant increase in glycosaminoglycan synthesis. That is, ASU had a disease-modifying effect, which is probably what your veterinarian is basing his recommendation on.

When it comes to choosing supplements there are many factors to consider, with research being one of them. You also have to take into account levels of key ingredients, cost, palatability and probably the biggest factor: how does my horse feel and move while on this product? For reasons I cannot explain, some horses seem to do better on a certain brand or with certain ingredients while other horses respond to a different brand or different ingredients. Since you and your vet know your horse best, I’ll step back and let you guys choose the product that is in his best interest!
9
Question: What are your thoughts on feeding naked oats? The nutrition value in protein and amino acids, fat, easily digested starch and in bonus avenanthramides is certainly the number one grain. What do you think?
Answer: 
I’ll admit, I had to look up “avenanthramides” to learn that they are a type of oat phytoalexin that exist predominantly in the groats of oat seeds and have antioxidant and anti-inflammatory properties. Now I finally know why oatmeal baths and shampoos can be so soothing to skin after a sunburn or poison ivy outbreak! And just so everyone is on the same page, hull-less or “naked oats” are high-fat (12-15%) varieties of oats that have been produced which are higher in energy than traditional oats.


In addition, hull-less oats typically contain more protein, including higher amounts of the limiting amino acids lysine and methionine. However, they also contain more phosphorous, so owners need to make sure the rest of the diet has appropriate levels of calcium to ensure the ratio between these two macrominerals is correct. So there are some pros to “naked oats” and some cons, and as long as you understand which type of oats you’re buying (with the higher price tag for hull-less oats this shouldn't be too hard) I say avenanthramides away!
10
Question: My horse appears to overproduce oil on his head. Could this have anything to do with his diet? His hair falls out in patches as though it is not being hosed down properly, but slowly grows back. Then the cycle begins again. This only happens when he is in full work. 
Answer: 
While there are some nutritional deficiencies and excesses that manifest as skin and hair conditions, I’m not sure this is the case in your situation. I recommend having your veterinarian out to examine your horse and perhaps take some skin and hair samples to get to the bottom of the problem. At the same time, you’ll want to share your horse’s complete history with your vet as well as what you’re feeding your horse, including when and how much. Hopefully, between the physical examination, biopsies or cultures, and evaluation of your horsekeeping and feeding, a diagnosis can be reached and appropriate treatment started so you can get back to enjoying riding!
11
Question: I have three Quarter horses and a Tennessee Walking horse. Their diet consists of a high quality forage (hay and pasture) with a mix of pelleted feed (low carb/no corn) and timothy pellets, supplemented with Gro strong vitamin and minerals, freshly ground flax seed, and biotin. They look great with a body condition score of 5 to 6. I have searched for a grass hay based feed that does not contain wheat middling or beet pulp. The commercial feed manufacturers do not consider wheat middling a grain since they sell 'grain free' feeds with wheat middling as the primary ingredient. What is the nutritional benefit of the wheat middling to the horse, or is a cheap filler?
Answer: 
Sounds like you’re doing a great job feeding your horses! To answer your wheat middlings question, I turned to AAFCO (Association of Animal Feed Control Officials), who defines it as a grain by-product that “consists of fine particles of wheat bran, wheat shorts, wheat germ, wheat flour, and some of the offal from the ‘tail of the mill.’ This product must be obtained in the usual process of commercial milling and must contain not more than 9.5% crude fiber.”


My other go-to source for equine nutrition, The Sixth Edition of Nutrient Requirements of Horses, says the inclusion of wheat GRAIN in horses diets is somewhat uncommon. However, wheat by-product feeds are often used in horse feeds, wheat middlings (midds) being one of the most common. Because most of the flour has been removed, wheat midds are higher in fiber and protein, but lower in energy than wheat grain. Wheat midds may contain more than one percent phosphorous so calcium supplementation is usually necessary when wheat midds constitute a significant portion of the diet. Due to their fine texture, wheat midds are not easily fed alone; however, they are commonly used in pelleted feeds.

Let me see if I can translate some of this nutrient-speak. First of all, don’t be alarmed by the use of the word “by-product.” I know the term scares some people off, but it doesn’t necessarily mean an ingredient is bad, all it means is that some ingredients, such as wheat midds, are not the main reason for processing wheat, which is primarily used to make flour for people. Because wheat midds are a by-product, their quality and nutrient composition can vary, but in general; this ingredient is high in protein, energy, starch, phosphorous, and potassium, with some trace minerals and vitamins to boot. So it does have nutritional value to the horse, and for this reason, as well as the fact that it’s fine texture helps bind pellets, you’ll see it in many commercial horse feeds.

Ask the vet:Colic

If you own horses long enough, chances are you will be faced with the threat of colic. Get the answers first by posing your questions concering the topic of colic to our month's AAEP expert, Dr. Christina Hewes.

1
Question: I have a 17-year-old Thoroughbred with a history of gas colic - usually about 3 episodes a year - and is a mild cribber. He is turned out on pasture 24/7. A couple of months ago, our barn switched feed and since then, he has increased his cribbing and has become more gassy. With his history, my veterinarian believes the cribbing is a sign of gastric distress brought on by the feed and recommended that I find a different feed (he said that the new feed might have too much sugar as the feed bag says that the pellets contain molasses). What do I need to look for in a feed? He is already getting pre- and probiotics.
Answer: 
I agree with your veterinarian that this new food seems to be upsetting his gastrointestinal tract. I would look at the previous feed that did not cause problems and switch back to the original feed or find one very similar to it by looking at the ingredients, not the percentage of protein, fat, or fiber. I do not know which ingredient upsets your horse's system in the new feed. It could be the molasses or it could be something else. The only way to know is by comparing the old and new feeds.
2
Question: My 22-year-old mare coliced and after the episode, the veterinarian recommended I put my horse on an ulcer medication. Why would my veterinarian make this recommendation? I have owned my horse for 12 years and she is a very easy keeper as this colic episode was her first that needed the attention of a veterinarian. In the past, she has had two mild gas colics.
Answer: 
This is a tricky question since I did not see your horse. A large percentage of horses have been found to have ulcers in their stomach. Ulcers can only be accurately diagnosed by placing an endoscope (medical camera) into the stomach to visualize the inside lining. Many vets have found that treating for gastric ulcers can resolve colic in some horses, whether or not the horses have ulcers. It may help to lower the gastric acid levels, which the ulcer medication does, to reduce some intestinal discomfort. Although your horse seems to be at a low risk for ulcers, ulcers or intestinal irritation still could be present. If the medication helped your horse, there may have been something irritating the intestines that reducing stomach acid helped.
3
Question: My horse went into colic mulitple times over the winter. Finally, the last veterinarian that came out to treat my horse, determined that the horse needed to take Sand Clear every day. The product says to only take a week a month but the veterinarian insists it must be taken every day due to the shale on the property. Is it safe to feed Sand Clear everyday?
Answer: 
There are different opinions on the use of psyllium, which is the active ingredient in Sand Clear. I prefer to give it one week of every month. Horses can develop the ability to digest psyllium in the colon, especially if they are receiving it everyday. This would prevent the psyllium from moving the sand through the colon. By feeding it intermittently, the horse is less likely to develop the ability to digest it so it can still help move the sand/silt through the intestine. Another thing to consider is using probiotics to help keep the intestinal bacteria working appropriately. This can improve the colonic motility and help move sand out. One study found significantly more sand was passed through the intestinal tract when probiotics and psyllium were given together.
4
Question: Does coastal hay cause colic?
Answer: 
Coastal Bermuda grass hay has been associated with feed impactions in the ileum, which is a portion of the small intestine. Some of these impactions resolve with nasogastric tubing with water, mineral oil, and electrolytes, while a small number require surgery. With that being said, many horses eat coastal hay regularly without a problem. Having good quality hay is very important so if you need to feed coastal hay due to your situation, many horses will tolerate it without colic.
5
Question: I have an 8-year-old Thoroughbred mare that developed spasmodic colic after getting cast in the stable two years ago. Since then, she has had a number of spasmodic episodes with the last one for a period of 36 hours. She lost a lot of weight and is currently on haylage and a high fiber, slow release mix. She is getting little turnout or grazing, but is being worked and hacked out 3 to 5 times a week. Is there anything else I should do to maintain her and stop the incidents of colic?
Answer: 
Chronic colicers are always tricky to manage. In some of the scientific studies they have found that horses that live on pasture have the lowest rate of colic. If you could find a situation where your mare is turned out for most of the day, it may help her. The movement in the pasture seems to improve the ability of the intestinal tract to move gas and feed material. If a pasture is not an option, getting her out every day for some activity is important. It can be just hand walking if you do not have time to ride. You may also want to note if there are certain types of feed or weather patterns that correspond to her colic. If she colic's when it rains, you want to ensure that she is getting some extra exercise on those days. If she colic's when fed a certain type of hay, try to find one that seems better.
6
Question: The stable where I board my horse has very sandy pastures. The horses are in a dry lot for all months except a few in the summer when the grass is tall enough. Is it a good idea to give my gelding a 7-day dose of a sand-clearing supplement like Arenus Assure Plus (a pelleted psyllium based feed additive with synbiotics and controlled release digestive aids. This patent pending pelleted combination of psyllium and digestive aids removes all of the sand and silt from the large colon)? On the other days of the month, I give him just the regular Arenus Assure (a granular daily feed additive with psyllium and synbiotics that improves the environment of the colon and improves normal digestive processes). I feel these are good preventative steps - as I have already lost a horse to sand colic. Do you feel this is a safe plan?
Answer: 
Sand colic is a difficult type of colic since horses tend to ingest sand when eating from the ground. The only way to prevent sand colic is to prevent sand intake. Feeding inside a barn or on a mat can reduce sand intake. Since this may be difficult in your situation, a one week course of psyllium is a good idea. I tend to have horses fed psyllium for one week a month and then have no psyllium for the following three weeks. This seems to prevent horses from obtaining the ability to digest psyllium, which is possible if fed psyllium constantly. For the products you are looking at, they both have psyllium in them so I would want to ensure that the Plus version has more psyllium than the other version. I might also try to find a supplement without psyllium that can be fed daily and add the psyllium for one week per month. Also, I do not think there is a  feed supplement that can remove all psyllium from the colon despite the label claims. If a product worked that well, then we would recommend it to all horses. At this time, intermittent psyllium seems to be the best way to prevent a large buildup of sand in the colon.
7
Question: Why is it so important to not let a horse with colic roll? 
Answer: 
This is a very common question. It is important to not let a horse with colic roll since they can injure themselves when they are rolling. The rolling rarely causes the intestine to move into an incorrect position but is a sign of the pain caused by the abnormal position of the intestines. If the horse is trying to roll, I recommend walking them to distract them from the pain and possibly relieve the cramping from the colic. Walking can also help the gastro-intestinal tract expel gas, which may relieve the colic pain. If the horse is sitting or lying quietly, the horse can be left alone until the veterinarian arrives to examine him. If the horse is uncontrollable and trying to roll, everyone needs to stay out of the way so they are not hurt by the painful horse.
8
Question: What diagnostics should be performed on an 8-year-old, otherwise healthy, gelding that frequently (every 1-3 months) suffers from low grade gas colic? His manure consistency and volume remains unchanged, his feed remains the same as does his stress level. He lives in an acre field (dry lot under trees) with a 21-year-old companion. They both have access to ample fresh water and frequent small feedings of quality grass hay. The hay is fed in slow nets tied inside clean plastic livestock tanks. Aside from 1/4 cup flax, mineral supplements, and regular psyllium doses mixed in grass hay pellets, and a carrot or two, he's not ingesting anything other than hay (the bark on the trees remains untouched, the fencing is plastic/Centaur, the field is covered with fine pine chips). He has had a tendency to colic since my daughter purchased him as a yearling, but now that he's living at our home and not a boarding facility. We notice his discomfort more often (appetite diminished, lying down and getting up, flehmen response). He often walks and passes gas as his way out of the discomfort, but we need some help for the poor guy!
Answer: 
This is a complicated question since it sounds like you have made a good environment for him. It sounds like your gelding is either producing too much gas or has a motility disorder in his intestinal tract, which could be secondary to inflammation. I would start with a fecal exam to look for parasites, even if he is regularly dewormed. I would then consider adding a probiotic to his diet since he is producing excess gas on a regular basis, which may help normalize the bacteria in his colon. If he is on any medications, I would ensure that he needs them and consider side effects, which could upset his gastro-intestinal system. Another thing I like to do is ensure he is getting enough activity with daily exercise form riding, lunging, or hand walking. Although he is in a pasture and should be walking around often, he may not be active enough. Another diagnostic is a gastroscopy to look for gastric ulcers even though he is in a low stress environment. A final option is to try a different type of hay to see if it produces less gas in colon. If you change his hay, it should be done gradually by adding small amounts of the new hay to his old hay. The amount of new hay should slowly increase and old hay decrease over a 1-2 week period to transition him to the new hay.

Ask the vet: Immunizations, Have you vaccinated your horses yet?

The weather is perfect, trail rides are beginning and so is the show season. Have you vaccinated your horse(s) yet? Pose your immunization/vaccine questions to our AAEP month's expert, Dr. Christina Dayton-Wall during the month of May.

1
Question: My current boarding barn requires vaccination for Strangles. My horse has been exposed to Strangles several years ago at a former boarding barn, but did not get sick. My veterinarian recommends using the killed virus vaccination if I absolutely must get it. What
do you think?
Answer: 
This is an excellent question because you are certainly not alone in this situation. There are definitely some options and you may need to discuss your situation with the boarding barn management. Since the horse did not contract Strangles, but was possibly exposed, I would recommend to test your horse's titers or level of immunity to Strangles. If the titers or levels of antibodies are high, I would not vaccinate and show the proof of titer to your boarding barn manager. If he or she has low titers then I would consider vaccinating with a killed or modified live vaccine (MLV). The killed vaccine is intramuscular (IM) and can cause muscle soreness, swelling, or even abscesses. The MLV is an intranasal vaccine and protects the mucosa in the upper airway. The side effects I see to the MLV is occasionally a runny nose from the nostril it was administered in.
2
Question: My horse has had terrible reactions to his vaccinations, which began 3 years ago. He now is vaccinated only for the West Nile, Eastern, Western and Tetanus and I have been admitting him to the equine hospital so they can treat/pre-treat and monitor him for any reactions. The reactions have been severe hives and, to the rabies vaccination, terrible pain as well. He recently had another bout of hives - cause unknown. Would a supplemental antioxidant offer a boost to his immune system? I currently give him Platinum Performance - but since he is now hyper-sensitive, would you advise I add something else and, if so, what would you recommend. He is a 15-year-old, pink-skinned Palomino Morab.
Answer:
I am sorry to hear that your horse is so sensitive to the vaccinations, but it seems like you are managing the situation well. I think the Platinum Performance is a great product! I feed it to my horses and have for years! Another option that I would add in would be Vitamin E. I suggest that you supplement with 400-1200 IU daily based on how much exercise your horse gets. There are several supplements on the market that provide Vitamin E. Some are liquid and others are pelleted. Consult with your veterinarian to determine if you also need to supplement selenium based on your geographical location.
3
Question: In New England, I always did my vaccinations in March/April. Now I am advised to either do West Nile later such as the end of May so that it will last through the fall as our autumns are getting warmer. The other option is to vaccinate twice, Spring and Fall. My horse has COPD and navicular, which I am managing with medication, but I don't want to over vaccinate. 

If I don't tend to board my horse off the farm, but do attend day shows, would you vaccinate FluRhino twice a year for a COPD horse? I was concerned after the last vaccination he coughed quite a bit.
Answer: 
Since your horse has some medical issues such as the COPD and he is already an immune stressed horse, I would recommend limiting the amount of immune system stress. This means that I would try to limit vaccinating your horse to once a year. Most horses I would recommend vaccinating semi-annually, especially in areas with lots of mosquitoes! I would
probably try to vaccinate in early to mid-May, that way your horse is fully prepared and his immune system is protected from West Nile and the encephalitis'.


For your second question, regarding the Flu/Rhino vaccinations and the stress that it caused your horse, I have a couple of recommendations. I would recommend maybe trying a different brand of vaccines. Your veterinarian may be able to order a vaccine from a different manufacturer and this may cause your horse less stress and less side effects, but still protect from the diseases just as effectively. Another option would be to pre-medicate your horse with a dose of an anti-inflammatory. Your veterinarian can help guide you with this. This may help prevent any increases in your horse's inflammatory state in relation to receiving the vaccine. If you are traveling a lot to day shows, I would still vaccinate twice a year. Another way to avoid risk when you go to shows is to limit your horse's exposure to strange horses. Do not allow nose to nose horse interactions. Don't share buckets, or rags used to wipe the horse's nose. Try to limit your horse's contact with items strange horses may have used. If you have to use a stall at a show, consider using a disinfectant prior to allowing your horse into the stall.
4
Question: Is it still recommended to vaccinate for all three (3) forms of equine encephalitis (Eastern, Western and Venezuelan)? I notice a lot of the combo shots but only include two out of three (Eastern and Western).
Answer: 
What a good question! I too have also noticed the change in the vaccine combinations that are available. At this point in time, the American Association of Equine Practitioners recommends the Eastern Equine Encephalitis, and Western Equine Encephalitis as part of the core vaccines. I would say that the Venezuelan Equine Encephalitis would be a risk based vaccine. If the area you keep your horse in has had an outbreak, then I would recommend to vaccinate. Fortunately in the US, VEE has not been diagnosed for more than 35 years. The last cases were most notable in Florida. At this point, I would not vaccinate for VEE, but definitely EEE and WEE.
5
Question: There is controversy about "over vaccinating" humans, pets and horses. What is your opinion on this topic?
Answer: 
This is a very timely question. I believe that over vaccination can be an issue, however if your horse is in an environment that increases his or her exposure to disease, I recommend that you vaccinate. I recommend vaccinations based on the AAEP's core vaccines, which include annual rabies, Eastern and Western encephalitis, West Nile Virus and Tetanus. If you travel with your horse or keep your horse at a barn where there is a lot of horse traffic, I would strongly recommend that you also vaccinate for Equine Influenza (flu) and Equine Herpesvirus (a.k.a. rhino). You may also consult with your veterinarian regarding vaccinating for Strangles. I recommend that you vaccinate your horse based on his or her risk. For example, I practice in Georgia where with our mild winters and wet springs, I recommend semi-annual vaccines for EEE (eastern equine encephalitis), WEE (Western equine encephalitis), and WNV (West Nile Virus). I would recommend that you discuss what vaccines are appropriate for your horse with your veterinarian.
6
Question: Why does my 15-year-old Arabian mare get hives locally on her neck and shoulder after receiving her spring vaccinations? What should I do now and in the future to treat/prevent this?
Answer: 
This is an excellent question. A horse that gets hives on her necks and shoulders is having a mild reaction to the vaccine. If the horse gets all the vaccines at once, I would recommend to break them up and separate giving them by at least a week. This helps to allow your veterinarian and yourself to figure out which vaccine your horse is reacting too. Another precautionary step would be to give a dose of an anti-inflammatory prior to the vaccines to help decrease the reaction that your horse has. Your veterinarian can help determine which anti-inflammatory is the most appropriate.

Ask the vet: The foot: Structure, Function, and Disease

AAEP expert, Dr. Karen Blake, answers questions concerning the equine foot, including its structure, function and disease.

1
Question: I have a 9-year-old miniature horse that has developed chronic laminitis. At this point, he doesn't have significant sinking or rotation, but he is very lame. He is currently on banamine and a supplement from Smartpak called Smartflex Recovery. His feet have been trimmed and there were no problems with his sole or white line. He is receiving probiotics and timothy hay, and a very small amount of Safechoice feed. We don't really have any pasture right now, so that isn't a worry. He walks around, and he seems to lay down when he needs to. He's not stressed, no teeth grinding or grimacing. He actually seems pretty perky for as lame as he is. Is there anything else recommended for the daily management of this condition? I was told that this could take several weeks to months for him to improve. I just want to make him as comfortable as possible. 

What about vaccines for him? I'm hesitant to vaccinate him right now since I do not want to cause a huge immune reaction while he has all of this inflammation going on. There seems to be a huge difference in clinical opinions about risk vs. benefit. We have a lot of mosquitoes that should be emerging any day now. I feel like we should wait until there is some improvement in his lameness to vaccinate, but I don't want to start the process all over again if we can get him to improve.
Answer: 
Poor guy! The most important part of managing laminitis is getting the inflammation down, getting his feet supported (they make miniature-sized Soft Ride boots for minis), keeping him slightly confined (so he doesn't walk all over the place when he is feeling better) and keeping the weight off, which can be especially difficult in these guys. 


Remember that horses (and minis) should be fed 1-2 % of their body weight in hay. For a weight loss program, which almost all minis I see need and especially minis with laminitis, I use a 1% body weight amount. Therefore, a 150 lb mini would get 1.5 lb of hay broken into 2-3 feedings and add in Natures Essentials Enrich 32 to keep their Vit/Min balanced and keep giving them some protein, which is only used for muscle mass. I use this regime until I see significant weight loss. Then they can get bumped up a little to 1.5-2% bwt of hay.



Generally, I also recommend soaking the hay for 30-60 minutes (no longer) to rid the hay of sugars (grass hay especially has significant variation of sugar and can be as high as 30%, which is terrible for horses sensitive to sugar in their diet). 
Additionally, if the new grass is coming up, I restrict their grazing by using a grazing muzzle - I know they don't like it, but it is really important in keeping their weight down!

All these recommendations should help stop the process of laminitis for your miniature horse.


I would try to hold off on the vaccinations as long as you can, however you may also separate out the vaccination so that there's not so much reaction at one time.
2
Question: My 6-year-old mare is part draft and Paint horse. Her hooves flare out, typically to the back. Are there any good products for this? My farrier has never suggested shoeing as I mostly trail ride.
Answer: 
That is a common occurrence with draft feet - the pancake, as I like to call it. Keeping the feet trimmed with appropriate rounding of the exterior hoof wall will help keep the foot from chipping when it starts to pancake. It is possible that his bone alignment is slightly off, which will make the hoof wall less healthy to stand up to his weight. You could have some radiographs done to determine whether that is happening. 

Shoes will also help to some extent as they 'tether' the hoof wall to an immobile object, but the nails only go to mid-way back on the hoof and will not help if the rear portion of the hoof is the one flaring out. The biotin product I recommend is either the Nanric 100 mg biotin powder or the double strength Farrier's Formula (approx 74 mg biotin). Biotin can help with horn growth of the hoof as well as health of the horn.
3
Question: We rescued a 11/2 year old Quarter horse filly whose growth plate had been injured on her left front ankle due to the previous owner trying to ride her. She has arthritis starting in it and radiographs show a small piece of bone missing from the ankle. Would a Glucosamine and Chondroitin supplement help with that? We have a farrier also working on her feet.
Answer: 
Yikes! Yes, there is more evidence that oral supplementation is helping horses with joint disease. My personal favorite is the Cosequin ASU plus; it has the typical joint supplements plus avocado and soybean extracts proven to help decrease inflammation/improve joint health as well as HA (Hyaluronic Acid), which is anti-inflammatory as well. Smart Pak makes a similar, as does Grand Meadows. At this point, her fetlock physis (growth plate) has closed and the farrier work, I would recommend, is allowing her easy break over from whatever side is lower towards the ground/fetlock angles away from; this will decrease the stress on the joint.
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Question: I know that a normal landing of the hoof should be heel first or flat. However my 14-year-old gelding has one front hoof where the leg itself actually rotates slightly and he lands heel first, but slightly on the outside of the hoof. He has been trimmed and shod normally with both sides of the hoof even and has never had any lameness or other issues. He is used strictly as a trail horse. However, it is something that bothers me and I would like to know if there is a way or a need to trim and shoe him to land normally, or not. Is this an anatomical defect that can not be or should not be messed with since he is sound with the way he lands as is?
Answer: 
It sounds like your horse does have an anatomical reason to land on the outside of the hoof as he walks. This is common in horses that toe in or have slight rotations of their limb higher up. As long as your horse is sound and the farrier is cognizant of keeping the foot trimmed evenly, I would not change your program. Often times, trying to alter the horse's landing pattern actually causes lameness. It should be kept in mind that the horse may develop lameness over the long-term due to the landing pattern as it is bearing more stress on the lateral (outside) aspect of the limb, but that will have to be dealt with when it comes up (and it may never be an issue too!).
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Question: I trail ride my horses on mountain trails that have a lot of rock as well as gravel. Is it better to keep horses shod for rocky trail conditions or can the foot harden to non-painfully allow the horse to travel barefoot? Would barefoot abrade the hoof down too much with many miles of trail riding?
Answer: 
It really depends on the horse and how hard the footing is on the mountain. Some rugged horses can handle mountain riding without problems. For the most part, I believe that our domestic horses can't handle the mountain riding without some type of protective foot-ware. Shoeing is usually the easiest and least labor-intensive, but some people have success with Easy Boot Trail shoes, which they apply for the ride. These boots can have rubbing issues on the heels and pastern regions though and should not be worn at all times as the foot needs some fresh air to keep it thrush-free.
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Question: We took in an Appendix Quarter horse last summer. He now has, what appears to be, cracks from his frog up the heel to his hairline. He now has thrush. What is the best way to treat this, without further damaging more tissue?
Answer: 
I assume the crack you are talking about is in the middle of the frog and up between the heel bulbs. This is usually caused by sore heels and a decrease in use of the frog. As the heels get sucked upwards, the crevice/crack gets very deep. Your veterinarian can treat these horses by paring away excess frog, even using a scalpel blade to be more precise as the frog gets deeper, then using either a kopertox or sugardyne mixture to dry out that area. Also important is changing the shoeing so that the heel and frog come back down from their sucked up position as the foot gets more comfortable.
7
Question: How should laminitis be treated for a pregnant mare? She became mildly laminitic with no rotation and foaled just last week. Now without the hormones and the weight of the foal, how do I treat her to return her to soundness? She is currently on a low sugar diet and wearing padded boots that support the frog, and walks with no discomfort. Is there anything else I can do for her?
Answer: 
At this point, especially since she's doing well, it seems like there is nothing more I can suggest besides taking her slow upon your return to riding. However, if you think she is sensitive to insulin (Equine Metabolic Syndrome), then you can always test for those levels in her blood and monitor them so that if her insulin is rising in her blood, you can modify her diet and weight further.
8
Question: I just realized that my farrier cut the frog down to almost nothing on three of my horses feet. I fired him on the spot but wonder if there is anything I can do in the meantime?
Answer: 
Sometimes in the spring, with the wet weather and mud, it can be easy for a farrier to take a swipe of the frog or even sole too deep as they have been softened by the weather. One product I really enjoy is called Keratex - it's a sole hardener but can be used on the frog as well. It's a liquid, which can be painted on with a small paintbrush, already included with the product. I would apply it once a day for seven days, then go to 2-3 times a week. It's very useful for thin soles or soft soles too.
9
Question: What is the best, most accepted, correction for a horse with low heel problems? Do wedges only make matters worse?
Answer: 
Wow! That is a very difficult question to answer as many people have differing opinions on the best method to use to correct low heel problems. There are lots of combinations of flat or wedge shoes with wedge pads, which can elevate the low heel. Unfortunately, if the heel is collapsing or underrun, they can make the situation worse as the pad is placing pressure on the collapsed heel and that pressure adds leverage to the damaged heel and increases the crushing force, worsening the problem. However, some farriers are able to use wedge pads/shoes with great success. Alternatively, there is another method to help the low heel called a 'rocker' shoe which elevates the heel portion of the foot by using a round bottom shoe and allowing the horse to 'roll' to the area of most comfort which is usually the toe region and thereby unweights the heel region (which essentially elevates the heel). The goal with these shoes is the create a healthier, more comfortable foot so the heel will eventually grow out to a relatively normal angle (less low).
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Question: My Thoroughbred gelding went on a "joy" run last summer, going through deep fields, on two roads, and ran upon railroad tracks for quite a distance, total of 3 miles or so! When I caught up to him, he could barely walk. He kept pulling up one hind leg, then the other. As the day went on, he couldn't hardly stand. His muscles would become rock hard at times. The vet and I both did research to determine what was going on. (His labs were perfect, etc.) With and without the vet, I gave him bute and banamine, altering back and forth. I also started to give acepromozine for the relaxation of the muscles...(I told the vet and she agreed). After 7 weeks, he was better and just a walk under saddle was more than enough for him. I left out LOTS of detail, like uncertain if he should be hand walked vs. stall rest this whole time, etc. My husband wanted to put him down! The horse had good attitude during this entire process so I know he hurt but not to the point of euthanasia! 

He finally abscessed in one hind hoof, then a week later, the other hind. My farrier said that happens even though trauma to the hoof (no nail holes, bruising, etc. present) can be unknown or just a guess. My questions, finally--what do you think caused the abscesses? Hard road? Deep soil in field? He recovered fine, except now he hates the field and WILL NOT agree to be ridden out there! Now he's scared and gets way upset! Any thoughts on this? Thank you!
Answer: 
It sounds like your horse developed rhabdomyolysis (ie: tying up) after his exciting get-away. Commonly, the lab values will not rise until 24 hours after the incident. I agree with your farrier in that the blunt trauma to the soles will cause inflammation within the foot, which can cause serum build-up or even bruising (blood pocket) within the foot - both of which are easily infected fluids. Once the fluid is infected, it becomes known as an abscess where it causes lameness and needs to be released from the foot so the infected fluid can drain out.
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Question: I have been trying to research my concerns on-line, but have not come up with information pertaining to my gelding. Captain is a 12-year-old Paso Fino, used for trail riding (and not a lot at that). He's had a very easy life since I've had him (at 4 years of age) and he has not had any particular discipline stresses to his joints since I've had him, using arena work just for general warm-ups in which I use the rail and large 20 meter circles.

This past year he has developed a "popping" movement in both front fetlocks, and I feel it when riding, obviously.  I've been observing other horses in their movements and have not seen this type of action. The popping happens during the full motion of strides.

Last season, we applied an aluminum shoe with a very slight rear wedge, which helped and Captain traveled well over the trails, but there was still a slight visual of this popping. We removed shoes for the year, giving him time off to adjust, observing carefully for any discomfort (with concerns of tendon/ligament stress from angle change). Captain was sound and showed no stress.

I don't ride much in the winter, here, but am starting to begin short warm-ups (straight line riding) and the popping has returned to be very noticeable. There has never been any heat or swelling at the fetlock/pastern areas, nor any sensitivity to palpation. My vet/farrier are scheduled next week for hoof x-rays (I want a baseline) to ensure proper shoeing, to get reading of sole depth, and coffin bone structure.

My question to you:

Have you ever seen anything like this? My farrier and vet, both, concur that this is an odd joint action and suspicion tendon/ligament stress.I appreciate your time in reading this and
look forward to your response.
Answer: 
That is a difficult problem. I think your idea to get radiographs of the feet is an excellent idea. Sometimes, the foot angles will cause the suspensory to create an abnormal angle of the fetlock or pastern, which causes what I would call a pseudoluxation - a luxation of the joint, which is not a true or permanent luxation - and probably is the cause of the 'clicking'. Meaning, when you change the angles of the foot, as you experienced when you placed wedge shoes on your horse, the suspensory ligament drops and allows a more normal fetlock angle and 'corrects' the luxation. It is possible that there is some suspensory pain too which may cause the horse to not want to drop fully into the fetlock, the suspensory should be palpated by your veterinarian for discomfort or swellings. The hoof radiographs should help you to figure out these issues. Good luck!
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Question: My horse is recovering from a lameness and abscess that my vet contributes to a retained sole. I've never heard of this before in 40 years of caring for horses. How common is this? What can I do to prevent this from reoccurring?
Answer: 
A retained sole (also known as false sole) is when a separation occurs between sole layers of the outer hard sole and the inner soft sole; they separate and form a pocket. It's actually more common than you would think. In my experience, it develops when the horse has a thin sole (<15-20 mm sole depth as seen on a lateral/side view of the hoof) and either a deep bruising/inflammation develops, which separates the outer and inner sole. It most likely occurs from stepping on something hard like a rock, ice-covered pasture or hard arena footing. 

The pain can either come from the edges of the pocket, which press on the soft, new sole beneath or from direct pressure of the hard sole on the soft sole as the horse walks. The only way to rid the horse of pain is for your veterinarian to peel out the hard sole with a hoof knife. This gets rid of the pressure/pain from the hard sole and allows the soft sole underneath to become firm. It is imperative that the soft sole underneath be protected during the time it is getting harder so new new bruising occurs. Usually after it matures for 1-2 weeks, I then put a protective pad under the shoe for one shoeing cycle so that the sole cannot be bruised as its growing out.
13
Question: Is a "clubfoot" a heritable trait? 
Answer: 
This is a very good question and so far there is no proof that it is inherited. However, if you take a look at many young foals, you can see the clear difference in hoof angles, which leads me to believe it is heritable. That being said, if you know that the foot may be inherited, surgery can be attempted to correct the condition as it works much better at a younger age.
14
Question: I have a 5-year-old gelding with a club foot. He had check ligament surgery as a 2-year-old. We are still struggling to get a heel first landing or at least a flat footed landing. The farrier has tried wedge pads, which did not work. He is much better after letting his feet grow, but seems as though the toe was cut too short, causing his knees to buckle. His frog was atrophying so, at my suggestion, we had his shoes pulled. He was definitely headed in the right direction for the first two months as his frog was growing and he was landing flat footed part of the time. Now we have back slid and he is now walking on his toe again. Any thoughts?
Answer:
When the club foot does not respond to the check ligament surgery, it can be difficult to manage as an adult. The reasons for this can be several-fold. Firstly, it is possible that the foot, as you suggest, has been trimmed too short. Many farriers and owners want the foot to look normal after trimming. Unfortunately, the foot is anatomically abnormal at this point and should not have the heel trimmed short. Taking off heel to 'create a more normal angle' creates tension on the deep digital flexor tendon (DDFT). This creates pain within the foot as the deep is putting tension on the coffin bone, which creates pain in the laminae (attachment to the hoof wall) or small tearing of the laminae. Additionally, if the heel has been trimmed to short, the tension in the heel region decreases the blood supply to the foot, which slows sole growth. This means that, in addition to pain in the laminae and heel region, there is possibly a thin sole present which can be cut too short at trimming, causing solar pain and eventually change in the solar portion of the coffin bone. In addition, it is likely that your horse will not land heel first, he will most likely land flat footed, which is fine. If he is landing toe first, then he doesn't have enough heel present

I would encourage you to have an x-ray taken of the foot to see how thin the sole is and if there is any bone change in the coffin bone. The x-ray will help to determine how to properly align the coffin bone, which will allow sole and hoof growth. 

As to the question of the frog, it will always be abnormal as the foot structure is abnormal and a thin, sucked up frog is directly related to the angle of the hoof and coffin bone within the foot. Therefore, the frog changes with the shape of the hoof/angle of the hoof, which is different than an atrophied frog.

This is a difficult case to manage, as you have already experienced. Hopefully we could answer some of your questions and help get you and your horse back on track.

Ask the vet: deworming

Tired of knowing which dewormer to use? Or when to deworm your horse(s)? Learn all of the answers by posing your questions on the topic of deworming during the month of February to our AAEP expert, Dr. Chanda Moxon.

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Question: Are there any particular dewormers that will cause horses to have problems with recurrent uveitis? I have a grey mare that has recurrent uveitis, and I was told that certain dewormers can trigger an attack. Is there any truth to that? 
Answer: 
Equine Recurrent Uveitis (ERU) is one of the most common eye disorders in horses. It is an immune mediated disease with several hypersensitivities, and no specific cause. The hypersensitivities include, leptospirosis, brucellosis, Streptococcus equi (strangles), Onchocerciasis, and hoof abscesses just to name a few. The most common hypersensitivity can be linked to Leptospirosis. With this being said, ERU can be very frustrating to link back to a particular cause.

Onchocerciasis is a parasite that is associated with connective tissue. They are not found in the intestinal tract of horses like most parasites. They produce microfilaria, which most often migrate to the dermis and/or to the eyes of horses. The clinical sign most often seen with Onchocerca is dermatitis. There may be areas of scaling, ulcerations, alopecia, and pruitis on the skin. 

Onchocerca can be diagnosed by having your veterinarian perform skin and/or cornea biopsies .The treatment includes Ivomec or moxidectin, which are found in many of the intestinal dewormers. If your horse has a history of ERU and has been diagnosed with onchocerciasis, during treatment, the dying of microfilaria can incite ERU.

This question had me researching in a number of places for an answer. Equine Recurrent Uveitis can have so many causes and treatment options. I recommend working closely with your veterinarian and perhaps even taking your horse to an equine ophthalmologist, especially if your horse is showing any signs of skin problems. There could also be other parasites that I am not aware of that could cause the flare ups after deworming.
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Question: My mare has been rubbing her tail very aggressively, off and on for a year, against posts, walls, etc. One veterinarian told me it was pin worms. I have tried to use paste dewormers, including a dose two weeks apart of Panacur. It seems better, but not completely 100%. Do you have any suggestions? 
Answer: 
I agree with your veterinarian that the “tail rubbing” is likely due to Oxyuris Equi or Pin worms. We should also consider other causes of pruitis in horses, such as an allergic response to the insect Culicoides and/or the fungi, dermatophytes (ring worm). And for male horses, sometimes a simple sheath cleaning will help when they are rubbing their tails, while in females cleaning the udders will help.

But, let's get back to assuming it is Pin worms, a tape test can be performed by your veterinarian to diagnose them. Since your horse seems to respond temporarily after deworming, I would expect we are dealing with either parasite resistance with your dewormers or an environmental contamination issue and your horse keeps re-infecting herself. Pin worms have become resistant to some of the deworming products available. I would recommend using a Pyrantel Pamoate paste every four weeks for at least two treatments. I would also decrease environmental contamination by wiping the rectal area with baby wipes and clean all water/feed buckets, as Pin worm eggs are very sticky and attach to objects in the stall allowing for your horse to be easily re-infected.
3
Question: I just moved to Las Vegas, Nevada from Michigan and would like to know if I need to change my deworming schedule for my horses and deworm for different types of parasites since the weather is so much different in Michigan than here in Nevada.
Answer: 
This is a great question; however, many theories are changing in the way we think of managing equine parasites. The rule of thumb in histories past was to deworm as the seasons changed or every three months.

There are many considerations involved when dealing with intestinal parasites such as the age of the horse, the size of pasture, the number of horses grazing a pasture, and if pasture rotation is available. We have not had any new antiparasitic agents developed since the mid 1990’s, the current deworming products we have, we need to make them last. With this being said, there has been a great deal of parasite resistance developing with our current dewormers. The recommendations we are now making for “when to deworm” is to perform fecal egg counts before deworming. This is a very simple test that your veterinarian can run in the clinic and at that time your veterinarian can detect what parasites are found and give you a better understanding as to what deworming product will best meet your horse’s needs, as well as offer other environmental management recommendations. Often times, I have found that we are deworming when there is not a need to deworm at all. In Nevada, I would recommend taking a fresh fecal sample to your veterinarian every 3 months. I would expect with the dry environment, you will be deworming less often than you were in Michigan.

This new way of thinking is to act more as a preventative management and attempt to decrease your horse developing resistance, as well as keeping a chemical out of your horse’s body if there is no need to deworm.

Ask the vet: EPM

AAEP's Dr. Sandi Farris answers questions on the debilitating disease, EPM.

1
Question: On October 23, 2012 I witnessed my 18-year-old paint gelding slip in the mud. He then began to side pass to meet me at the gate. Our veterinarian recommended a week of stall rest, but my gelding had little to no improvement. The veterinarian said came to evaluate my gelding, which included a lameness exam and radiographs of the left stifle. His diagnosis was severe sprain of the interior stifle, heat and apparent inflammation. Treatment consisted of bute and work him lightly building on strength and duration and a one to two week normal turnout routine. This didn't feel right to me, but I complied. On day 2, my horse became extremely lame on his right as well as original left . I contacted the veterinarian once again to discussed the current situation and response to treatment. His response to me was to keep him moving. Over the next week, my gelding tried to comply but lameness worsened. I had a second veterinarian reevaluate my gelding. He disagreed with treatment and told me to rest him and continue on bute. Over the next four weeks, my gelding's lameness worsened and seemed to loose control of his hindend. He almost seemed to have no clue where his feet were and had a pronounced right hind hip drop when moving. He looked one step away from falling. 

Enter my farrier, who watched him move and suggested a lameness specialist and/or chiropractor. That said, a specialist came and did an evaluation, which included digital radiographs of both the head and stifle. She felt the horse definitely was neurologic in symptoms progressive of original injury. She felt there were three possibles, which included THO, EPM or West Nile. Radiographs showed moderate swelling of the right hyoid bone, and slight on the left. She started him on a high doses of Dexamethasone and would reevaluate him in one week, which did include some improvement. She then drew blood to hold for future EPM testing. I went online and watched several videos of EPM cases and felt this was what I was seeing in his movement. She then begain him on EPM medication along with Dexamethasone. Five weeks later he had significantly improved. I began walking him daily which we graduated to small hills backing and stepping over ground poles.

I now have two new problems. The first is that he has lost the hair over his left eye, and she thinks it is possible uveitis, which dex is used for. How do we know what drug is working on his ataxia, and dex is an immune supresser, could it be causing other problems? My specialist that took blood samples is currently out of the country as I would like her to run the bloods for EPM. But, what about the hyoid bones swelling? Is it possible this is and has been his normal all along and we are dealing with EPM? And the hair loss over his left eye; is this some kind of immune response to the drugs or the disease in question? My gelding has been good-natured and patient throughout all of this. However, I am confused and frustrated!
Answer: 
Oh my, you do have a number of issues in your horse right now. This case has a high number of variables between the early history of lameness and the response to EPM medications and finally a question about the hyoid bone and the hairloss. I can't comment on a diagnosis for your gelding but I can suggest either contacting your last veterinarian for guidance or if she is unable to re-examine him contacting a referral center that can take your gelding's symptoms one at a time. I don't know where you are located but most areas have fairly good access to a Veterinary Teaching Hospital or if you'd prefer, a local private referral clinic. Referral centers and Universities tend to see a number of unusual and/or complicated cases each year
and may have more diagnostic tests available to pinpoint a diagnosis for you.
2
Question: Is there a test available to see if my barn cats are carriers? If so, what is the name of it? Do most small animal vets perform the test or will I need ask my Equine veterinarian?

I own an 8-year-old Gypsy gelding that has been battling EPM since April of 2012. We first tried a course of the Sulfa suspension medication, and now he is running through a course of Marquis. I have been extra careful with keeping the wildlife carriers of EPM out of my barn, but would like to see if our barn cat is carrying it. 
Answer: 
Cats have been tested experimentally to determine if they carry serum antibodies to Sarcocystis neurona. Researchers determined the domestic cat is one of the natural intermediate hosts for the causative agent of EPM. Some studies report that 5% of all farm cats have been exposed to S neurona in areas with opposum. Your question about testing your own cats is a good one. Although research labs have used the tests it is not a common test in the private clinic setting. A Polymerase Chain Reaction (PCR) test is required to differentiate exposure of the cat to the parasite from actual infection with S neurona. Zoologix Lab, among others, does offer a feline S neurona PCR. It can be run on blood or nervous system tissue. Talk to your veterinarian about the practicality and use of this PCR in your barn!
3
Question: My 13-year-old Appendix Quarter horse mare developed EPM at the age of 7. The disease was very severe and I nearly lost her, but she recovered well. She is sure footed, rides well and even jumps. The only setback she had was one paralyzed vocal cord (per bronxhoscopy). She is now in foal and due March 12. She is exhibiting symptoms of EPM again. I know foaling is stressful, but wondered if Marquis would be safe to give her before foaling? If so, for how long? If not, can it be given after foaling with a foal at her side?
Answer: 
EPM is unfortunately a disease in which stress of the horse plays a large part in recurrence of symptoms. Pregnancy and lactation are arguably the most physiologically taxing periods in a mare's life. Sarcocystis neurona has a tendency to recur during these times. The resulting neurologic deficits cause concern about the health and safety of mare and foal. 

Current medications available for treating EPM can have a variety of adverse effects on a pregnancy and should be used carefully and under the advisement of your veterinarian. Risks and benefits to treating your mare while she is in foal will need to be assessed. Most commonly these drugs are folate-synthesis inhibitors which, as we are aware in human pregnancies, when used long-term can lead to birth defects and bone marrow arrests in the fetus. 

Medicating your mare with the foal-at-side may be safer than treating during the pregnancy, and again you will want to discuss the specific risks and benefits with your vet. The Marquis drug insert does contain the broad statement that risk of use in breeding horses is unclear.
4
Question: I live in north central Virginia and have an 11-year-old Irish Draft gelding. Can/should I vaccinate him against EPM? Can this vaccine be given with other vaccines or should it be done at a separate time? 
Answer: 
In the past, EPM vaccines were available on the market for use in horses. Protection in those horses was, unfortunately, poor, and the vaccines were removed from manufacture. As of now, there is no USDA-approved vaccine against EPM. What a help it will be when there is one with a high level of protection! The best horse owners can do now to protect against the protozoal disease is to minimize the intermediate hosts (opposum, cats, raccoon, and skunk are most likely culprits) by keeping grain and water sources secured, decrease host access to horse pastures, and keep your horses as healthy and stress-free as possible. I am sure the ongoing research will one day lead to a useful vaccine.
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Question: My 27-year-old mare presented the following symptoms on the evening of 11/8/12: barely able to walk; could not cross the threshold to stall without help, fell down in stall, which resulted in an emergency call to the veterinarian. They submitted blood drawn from my mare to MI State University for testing (S. neurona IFA Titer test), which was 320 suggesting + for antibodies against S.neurona. The clinical picture was consistent with EPM as well. She was then administered on a 28 day treatment with Marquis, which has shown improvement with her gait/balance, etc. I question that specific test as to what it is testing and have read that while the IFA test is believed to be an improvement over the Western blot relative to predictive ability; newer ELISAs are more quantitative. If the appropriate tests are used (whatever that would be) would a decreased antibody titer after treatment be useful? And, if symptoms re-appear, would it help to have this information and then re-test if I suspect a relapse?
Answer:
Such a good question...this is one of the toughest pieces in the EPM puzzle right now. Serum (blood) tests for EPM have improved over the past decade but still are not altogether definitive in diagnosing clinical disease caused by the EPM agent Sarcocystis neurona. The first test used was known as a Western blot, a procedure which was revolutionary in the 1990's but had limitations with a high number of false positives. Since then, polymerase chain reaction (PCR) and immunofluorescent antibody (IFAT) testing has improved the value of the results. Each test has individual limitations; a negative PCR does not rule out the presence of S neurona, IFAT may be more subjective than quantitative.

Research is ongoing and new methods are being developed. It is possible that enzyme linked immunoabsorbent assay (ELISA) tests may currently be an ideal choice for accurate test results. That said, an elevated S. neurona serum titer is evidence of infection (exposure) than of actual disease. Titer levels can vary based on the number of organisms found in the horse, the immune system status, and the presence of concurrent or previous medical treatment.  

Many cases of EPM are treated based on historical clinical signs in the presence of a strong serum titer. Presumptive treatment with an anti-protozoal with improvement in signs can be considered a diagnostic tool in itself. The most exciting new research Dr. Dan Howe, of the University of Kentucky Gluck Equine Research Center, has found proteins on the surface of the S. neurona parasite, which have the ability to create a strong immune response in the horse. The proteins, labeled snSAGs, elevate in ELISA titers on serum and cerebrospinal fluid (CSF). CSF is sampled via a spinal tap. Similar to previous testing methods serum snSAGs titers alone are not completely foolproof. CSF titers coupled with serum titers for snSAGs remain a more credible positive for EPM diagnosis. Check with your veterinarian for more information on using the newest snSAGs ELISA titers.
6
Question: My 13-year-old mare came up with a low positive on the EPM test when she returned to upstate NY from Va.as a 3 yr old. She was testy (wringing tail) about weight on her back and even tripped and fell once when being ridden but otherwise was perfectly fine. I treated her for one month with a medication that is now off the market. She never got wobbly but since I couldn't really make any progress with her dressage work, I stopped riding her. She is in foal now. Is there any way to know if the EPM was causing this behavior?
Answer: 
You don't specify which test was used in your mare; there are some differences in interpretation depending on the method used. Low positives on any serum (blood) test may indicate an early response of the horse to the Sarcocystis neurona protozoa, a low dose of S. neurona in the body, or may be a a cross-reaction to another type of sarcocystis and actually be a false positive. Because of the length of time that has elapsed it would be difficult to attribute your mares signs to EPM. 

Many other variables can play a part in the difficulty of bringing a sport horse up the levels.
Behavior, training, nutrition, and other musculoskeletal and orthopedic processes can lead to a wringing tail and gait deficits. Equine polysaccharide storage myopathy (EPSM or PSSM) and vitamin E deficiency are two specific disease syndromes that can cause some of the same signs as EPM. It sounds like she is no longer exhibiting these signs as she is currently in foal and hopefully healthy and well-fed. It is possible that EPM signs can return in horses that were previously infected, regardless of treatment history. Stress of pregnancy and lactation could provide an opportunity for pre-existing  S. neurona to "take hold" and create damage to the central nervous system. Watch for neurologic or balance and weakness issues in your pregnant mare and advise your veterinarian of her past episode of tentative EPM. 

A team approach would be ideal in determining if your mare should currently be assessed for EPM. A cerebrospinal fluid test exists that can be more definitive in making an EPM diagnosis, but it is not without risk to the horse and may not be a good idea in a pregnant horse. Pregnant mares must be treated for EPM with caution: sulfadiazine/pyrimethamine combinations (Rebalance is a brand) have been shown to have toxic effect on foals. Marquis and Protazil are safe and have been used in pregnancies, though none are specifically FDA-approved for use in pregnant mares.
7
Question: I have a 20-year-old Tennessee Walking horse mare that was observed as having hind-end ataxia in Fall 2009. I am located in Santa Fe, NM where we have a lower population of the carrier mammals. She came from Tennessee a couple of years prior. Could she have acquired the organism and not exhibited symptoms until 2-3 years later? Two blood titers performed in 2009 and 2010 resulted in nearly the same probability: 70-something percent chance that she has the organism. I administered one round of Marquis in 2009, which seemed to help with some strengthening of the hind-end and reduced stumbling. Since then, her symptoms have not changed significantly. Is this EPM or is something else going on? She has foaled 13-14 times in her past life prior to my ownership.
Answer: 
There are a few possibilities with your mare. Changes in muscular strength from age and multiple pregnancies and a history of living in an area (TN) with the carrier opposum species could all contribute to the hind-limb ataxia (unsteady, unbalanced) you describe. Nutrition, exercise, and regional disease could also be variables in a diagnosis in your girl. 



The organism of EPM, Sarcocystis neurona, can lie dormant in the horses central nervous system for years before a bout of illness, stress, or time alone results in disease symptoms. Stumbling, neurologic deficits, hindlimb weakness, and muscle atrophy, especially if asymmetric, are symptoms of EPM. The blood tests she received in 2009 and 2010 indicate that she has been exposed to and developed antibodies against S. neurona in her lifetime. This test is a useful tool to focus our suspicion on EPM, however the blood test alone is not definitive for a diagnosis of EPM. In some cases, owners and veterinarians decide to further identify the protozoa by collecting cerebrospinal fluid (CSF) from the horse. The spinal fluid is used as an aid in diagnosis in horses with active clinical signs such as those you describe in your mare. The collection of CSF is not without risk to the horse and contaminated samples can cause inconclusive or false results.


The CSF testing is often reserved for horses in which the diagnosis would significantly change the treatment plan or affect the horses performance or quality of life. In many cases, diagnosis is achieved by administering a round of EPM treatments, such as the Marquis product that your mare received, and assessing changes in the patient. Subsequent improvement in EPM signs can lead to a presumptive diagnosis of EPM. Once successfully treated, EPM may remain in remission for months or years, but multiple reports of horses with recurring neurologic symptoms indicate that the protozoa is a difficult parasite to eradicate.
8
Question: My Thoroughbred gelding is 24-years-old and has Cushing's Disease and now we suspect EPM. He is being treated for both. What are the odds of a full recovery from EPM - I mean will I ever be able to ride him again?
Answer:
According to current research information, around 70% of horses treated for EPM with appropriate medications and protocols will respond and return to their previous performance levels. Your horse is suffering from two separate diseases, however; so his return will depend on how readily each affected system (hormonal, or endocrine, and neurologic) is able to respond to treatments. There may be some overlap in symptoms from each disease. Hopefully the medications and management strategies will allow your guy to reach his full potential again. Your gelding is lucky to have you!
9
Question: My 11-year-old Appendix gelding was diagnosed/treated for EPM when he was 5 years old. He only showed very mild symptoms (easily pulled off balance with tail pull, stands "quirky" with legs crossed). I've ridden him moderately over the years, even doing some low hunter courses with him, but lately he seems to be getting weak. He slips and slides in our indoor arena, apparently not getting his hind feet firmly planted while cantering around. My question - can EPM return after a long "remission" and what can I do to strengthen my geldings' back and hindlegs so he doesn't slip so easily? Should we treat him again with medication?
Answer: 
Unfortunately, EPM is a disease process that can relapse after an apparently successful treatment regimine. The protozoal agent, Sarcocystis neurona, can lie dormant for many years before causing a horse to have any signs of neurologic instability. Weakness, balance deficits, lameness, and lack of coordination can all be symptoms of EPM. The same signs are found as well in a multitude of disease processes, including equine motor neuron disease, equine polysaccharide storage myopathy, and west nile virus syndrome. That said, I would strongly suggest having your veterinarian perform a full physical examination of your gelding to determine if an EPM relapse is happening. It is possible your vet will want to treat with another, longer-term course of medications. Traditionally sulfa drugs coupled with pyrimethamine were used to "paralyze" the protozoa. Newer drugs have come into use including ponazuril (Marquis) and nitazoxanide, or NTZ, (Navigator). Ponazuril is a form of a coccidiostat, a drug class that inhibits the replication of coccidia protozoa but may not effectively kill every organism in the central nervous system.  Nitazoxanide was originally developed for human AIDS patients and has also been found to kill the sarcocystis protozoa.  In the meantime, use caution working your gelding in order to prevent him from stumbling or falling and causing injury to himself or a rider/handler. Once he has been examined and a diagnosis made, exercises for restrengthening his topline and his hind limbs can include lots of walking, stretching his head, neck, and back long and low to activate his lumbar and gluteal muscles and lift his belly. Ensure that your arena footing is firm, not too deep, and not slippery. Walking up hills is an excellent strengthening routine once he is deemed safe to work.
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Question: We seem to have a revolving door of opossums in our barn, despite trapping and relocating them. My concern is obviously EPM. Do we know what percentage of opossums carry the disease and how easily they can transfer it to horses?
Answer: 
Opossums are a tricky business in some barns! Like rodents, they are drawn to horse and cat feed, low-lying water sources and human garbage. Opossum prefer densely forested environments and riparian areas alongside rivers and streams along the West Coast and the southeastern coastal states. Horses become infected with S. neurona after ingesting the protozoa from the feces of opposum on pasture or in grain or hay, even in feeds shipped across country. EPM has been reported in nearly every region of the United States. It is difficult to say precisely what percentage of opossum carry the protozoa, but it has been found that an intermediate host is necessary to complete the sarcocystis life cycle and cause infection in the horse. 
 
At this time, the natural intermediate host is not known definitively but is suspected to be raccoons, armadillo, birds, skunks, and/or cats. A study by Dr. Steven Reed et al found that 59% of tested raccoons were positive for S. neurona. Another study  reported in the Canadian Journal of Research that 7% of domestic cats carry the parasite. The good news for your barn is that although many horses are exposed to S. neurona by opossum, the majority are able to mount an immune response and prevent infection. Studies show that only 1% of horses will suffer neurologic disease after being exposed to sarcocystis. Unfortunately, young, old, ill, or stressed horses are much more at risk for clinical EPM disease. Because the horse is an aberrant, or dead-end host of S. neurona, positive horses can't infect other horses.
 
Management at your barn should include sealing feed containers and keeping cat food out of reach, using high-sided tubs for feeding, keeping your horses healthy and current on vaccinations and deworming, and feeding heat-treated pelleted feeds to minimize the infective sporocysts in the ingredients. Wire-mesh fencing may deter the opossum from entering the barnyard. Minimizing the presence of intermediate hosts will decrease the infected opossum population.
11
Question: I have a 23-year-old gelding that was diagnosed and treated for EPM, but not sure when....at least a couple of years ago. He has been having the hind leg spasms since I've had him (one year now), but over the last month or so, he's occasionally been suffering from narcolepsy. He catches himself before he falls. He has also been stretching out his stance when just standing around. Are these signs of progression and will it become worse? I have given him ABC's holistic supplement without folic acid, but will this help him? He is in good weight, has a good appetite but doesn't lay down to sleep very often. Anything I can do for him? ANY info you can give me about EPM and what to do for him will be greatly appreciated.
Answer: 
A horse with Equine Protozoal Myeloencephalitis (EPM) may exhibit a variety of neurologic symptoms, including poor balance, spastic leg movements, or the signs you describe with the appearance of narcolepsy. Sarcocystis neurona, the parasitic protozoal agent of the disease, is found most commonly in geographical areas inhabited by the opposum. Horses that graze pastures where opposum have defecated are most at risk for acquiring S neurona. Amazingly, a number of these exposed horses never show EPM symptoms though some horses will harbor the dormant parasite for years before becoming ill. 
 
Given the history you mention, I suspect your horse is one of the 10-20% of patients that suffer a relapse of EPM after previous successful treatment. A veterinary examination of your horses neurologic system and physical condition would be ideal at this time. Your veterinarian can help rule out other causes of 'narcolepsy' such as sleep deprivation leading to the buckling you describe as well as determine if another round of EPM antiprotozoal treatment would be useful. 

Ask the Vet: Orthopedic Surgery

Do you have concerns regarding orthopedic surgery on your horse? Pose your questions during the month of October to our AAEP expert, Dr. Chris Bell regarding orthopedic surgery, what to expect before and after.

1
Question: My horse recently had arthroscopic surgery. He was bleeding into the tibiotarsal joint in his right hock. The surgeon discovered a very large fibrous band of tissue in the joint that had a blood vessel in it. He felt it was so large that he could not resect it without significant risk, and it was too large to use a laser. He had never seen a case like this previously. Have you run across any cases like this? If so, were you able to resect the fibrous band of tissue? Are there other methods available to shrink the band of tissue? Could the bleeding into the hock cause the band of tissue to develop? If you have observed these types of cases, what was the outcome post surgery? I sincerely hope you will respond as this is so rare. I am trying to find any experts who have dealt with cases like this so I can help my horse make a full healthy recovery. Thank you for your time.
Answer: 
Thank you for your question. This does sound like an unusual case. I suspect the large fibrous band could have been due to the previous bleeding into the tibiotarsal joint. As the blood components reabsorb from the joint, they can sometimes leave behind a sticky fiber substance called fibrin. This fibrin will stick together and can form bands or webs. These bands then mature into a fibrous tissue. I have seen this before in different joints and tendon sheaths. Often these bands can be appreciated on ultrasound as well as during arthroscopic surgery. 
 
In most cases, these fibrous bands can be resected but in this case, it sounds like the surgeon had seen a possible blood vessel within the band. That is very unusual and could limit the ability to resect.
 
As far as your options to remove the tissue, it will depend on how large the blood supply is to the tissue and where the tissue is located within the joint. It may be more web-like tissue than a distinct band of tissue - difficult to tell you the exact options without seeing this band. Potentially, the surgeon could ultrasound the joint and identify the size of the blood supply in the tissue. If there is no major blood supply then the surgeon will be able to go back into the joint and resect the tissue. If there is blood supply, then the surgeon may be able to apply hemostatic poly-L-lactate clips to the blood vessel and then resect the tissue. Another option for the surgeon would be to perform a arthrotomy (open the joint) and remove the tissue. This type of approach would allow good visualization for the surgeon during surgery if there was bleeding but does carry an increased risk of infection and is not as cosmetic as arthroscopy post-operatively.
 This is a rare case and I wish you and Rex all the best. I am sure your surgeon will be happy to discuss your options from this point forward and I am hopeful that this does not limit his future athletic performance or comfort.
2
Question: This is follow up on the 2.5 year old Quarter horse with the patella luxation. Radiographs indicated no ligament, tendon, or knee cap damage as the ridges appear to be fine (Dr. Dunlap included the views you recommended). We are trying 6 to 8 weeks of rest in a 24 x 36 paddock, hoping the strain heals and patella will reseat. He is not experiencing any pain or lameness. In your experience, does this type of injury, correct itself? Thank you for your suggestions.
Answer: 
If the ridges appear normal, then the luxation is likely due to trauma and the patella needs to be reseated into the trochlear groove. In order for the patella to luxation, there was stretching of the collateral ligaments of the patella. If the patella is reseated and the horse is rested (as your veterinarian is recommending), then there is a potential that the collateral ligaments and collateral structures, which hold the patella in place, will scar and heal. In some cases, the patella will need to be surgically repaired and the surgeon will perform a procedure to strengthen the torn collateral ligament structures of the patella. 
 It is important that the patella is currently reseated during the rest phase of the recovery otherwise surgical correction will likely be required to keep the patella seated in the correct position. Best of luck!
3
Question: Is it recommended to do surgery by cutting the flexor ligament in a horse that has an 11 degree rotation of the coffin bone?
Answer: 
Cutting the deep digital flexor tendon (DDFT) is one option to help treat rotation of the coffin bone. The surgery is performed to relieve the tension of the DDFT on the back of the coffin bone and thereby, hopefully, prevent further rotation of the coffin bone within the hoof. There are no hard guidelines for when to cut the DDFT. Some soft guidelines include greater than 15 degrees of rotation, refractory to pain management, presence of the coffin bone through the sole. These are guidelines only. 
 
There are several other options available to treat rotational laminitis. Depending on the severity and rapidity of the laminitis onset, other options may include, anti-inflammatories, cold therapy, padded frog support shoes, Styrofoam shoes, derotational shoeing treatments, etc. 
 
You should discuss all the possible options with your veterinarian and farrier before making a final decision. Some horses can return to some form of athletic work after DDFT transection (cutting the flexor tendons) but the decision should be made once all other options have been weighed and considered.
4
Question: My 2 1/2-year-old Quarter horse gelding, has dislocated his knee cap. My veterinarian said it is from a possible slip/sudden twist that could have caused the problem. He is not lame or experiencing severe pain. The knee cap slips out of position when placed back in position. The course of action is 10cc benamine for five days and stall rest. His training has been ground manners and ponying with a reliable trail horse. He has carried a saddle, but never had weight on his back. Is surgery down the road for him? What are his chances of being more than a pasture ornament? I will keep him as that if that is what will keep him healthy.
Answer: 
Thanks for the interesting question. Luxation (dislocation) of the patella (knee cap) is fairly rare in Quarter Horses. It is seen more commonly in minature horses and ponies. The cause is often related to an anatomical abnormality in the end of the femur bone (part of the stifle joint). It is good that your horse is not in pain and able to move around normally. Once the five day prescribed course of anti-inflammatories is finished, your vet may want to take some radiographs (x-rays) of the stifle joint to confirm that the patella does indeed luxate and the position of the patella once luxated. 
 
In addition to the standard views of the stifle, your vet should take a skyline or flexed skyline view of the stifle joint/patella. The vet will need to look at the end of the femur bone and see if the trochlear ridges are normal. These ridges help hold the patella in the proper position. In horses with a luxated patella (dislocated knee cap), one or both of these ridges will be malformed or missing. This will be important to know in order to determine if surgery is needed. 
 
Once the radiographs are taken, your vet may refer your horse to a board certified equine surgeon for a consultation. In some cases, surgery will be required to correct the malformed femur and in other cases a more conservative approach may be available to help stabilize the patella and patellar ligaments.Once you have some more information about exactly what is going on, your vet will be able to give you a better idea of your horse's future athletic prospects. All the best!