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. Always make changes slowly over 10-14 days, this allows time for the micro-flora to adapt to new food. A kitchen food scale is important, every food has a different weight per scoop, and feeding directions is likely in pounds. 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! 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. A 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

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. Always make changes slowly over 10-14 days, this allows time for the micro-flora to adapt to new food. A kitchen food scale is important, every food has a different weight per scoop, and feeding directions is likely in pounds. 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! 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. A 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

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 8^th 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 8^th 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.