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November 2017 - AAEP is on Stall Rest

AAEP is taking the month of November off from "Ask the Vet", but will be back in December to answer your equine health questions concerning winter weather care for your horse with expert, Dr. Christine Tuma.



Click here to read this month's questions and answers.
  1. My 9-year-old Appaloosa/Quarter horse gelding was diagnosed with navicular changes and fraying of the Deep Digital tendons in the bilateral front feet. He has crushed heels and had long toes before I took him on. He has had Osphos/HA and steroid injections to the navicular and Prostride injection to the navicular bursae. He is actually beginning to do really well now. Injections were administered on August 18, 2017. I am hand walking him and he has supervised turnout in a round pen. I am just starting to work with him on the ground and we are trotting for short periods on a lunge line. How should I continue to progress with his rehabilitation at this point? I was told I could ride-walk him for short periods, but have not done that yet as I would rather be conservative. My farrier has also helped to attain a much better hoof-pastern axis and we are trying to encourage heel growth. (View Answer)

    First off, I want to commend you for your conscientious and thorough care of your horse. It sounds like you are very invested in his well being, and that he has had great care up to this point.

    Based on your description of the lesions, I am assuming he was diagnosed with tendon damage and navicular changes via MRI, as it can be very difficult to visualize tendon fraying within the hoof capsule by other means. However, sometimes the assumption of soft tissue involvement is made based on radiographic findings and clinical lameness; the navicular bone is intimately associated with the deep digital flexor tendon as well as several delicate ligaments.

    All of the treatments you mention are very reasonable for his condition, as bisphosphonates like Osphos can reduce navicular bone remodeling, hyaluronic acid can help lubricate the navicular bursa, and steroids and Pro-Stride can reduce inflammation. Shoeing changes are also a huge component in the management of navicular syndrome, as long toes and low heels can greatly increase the strain on the navicular bone and deep digital flexor tendon, making the latter prone to tearing. It's great that you are working with a good farrier; it sounds like you are already shoeing based on radiographic assessment to ensure the angles are appropriate, but if not, this is definitely something I would recommend. Keeping on top of his feet will remain important throughout your gelding's life.

    Regarding return to work, my recommendations would depend on just how severe the tendon damage was. If there was extensive injury to the deep digital flexors, like you, I would err on the side of being more conservative before bringing him back into work. The treatments you have already pursued should minimize his risk of relapse, but once damaged, tendons are predisposed to reinjury. I would generally recommend a minimum of two to three months of rest (in a stall with gradually increasing, carefully controlled hand-walking) following initial diagnosis and correction of hoof angles prior to pursuing ridden work, and potentially longer if the damage was very severe. After this point, if the horse appears sound when jogging in-hand in a straight line, I would add riding at a walk, avoiding sharp turns, deep footing, and uneven surfaces. I would gradually increase the time spent riding at a walk to daily 30 minute sessions over a six-week period (starting with 5 minutes and slowly increasing), then would add work at a jog, again avoiding sharp turns and bad footing. Trotting should be introduced slowly, starting with 5 minutes per session and adding an additional 5 minutes every other week. Cantering should be avoided for the first several months of reintroduction to under saddle work (and should similarly be introduced slowly), and full turnout should not be permitted until the horse is cantering well with a rider. If the horse continues to do well once cantering for longer periods of time, regular training for his discipline may resume--this is usually at least nine months post diagnosis.

    If at any point lameness is noticed, you should immediately drop back in exercise intensity and consult your veterinarian. Additionally, if the tendon lesions were visible ultrasonographically, it would be a good idea to have another ultrasound performed to assess progress prior to putting your horse back into work. It is possible that he will require more injections in the future to help manage his condition, but his progress (and your veterinarian's guidance) will help you determine this. Good luck! Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  2. Could you explain how Omega-3 can help with hives? My soon to be 23-year-old mare has them from time to time beginning in the spring until late fall. She is not itchy, but rather can get very big different shapes all over her body. They tell me this might help if I start her on it now. (View Answer)

    I'm glad your horse isn't itchy, as severe hives can certainly make a horse extremely miserable, especially in hot weather. Omega-3 fatty acids are sometimes recommended for the control of skin disease and other inflammatory conditions because they have anti-inflammatory properties. Briefly, Omega-3 and Omega-6 fatty acids are two types of "essential" fat, meaning they must be consumed in the diet to maintain health (and both are found in a horse's usual food, in varying quantities). While Omega-3's are often thought of as the "good guys" (anti-inflammatory) and Omega-6's are considered the "bad guys" (pro-inflammatory), the truth is that both are required to support essential functions. The goal in supplementation is to increase the ratio of Omega-3 to Omega-6 in the diet, to tip the balance toward the anti-inflammatory side; however, we do not fully understand the ideal ratio. Several studies have shown potential benefit in horses receiving Omega-3 fatty acid supplementation in the management of equine asthma, osteoarthritis, and skin hypersensitivity. Often the supplements are used as adjuncts to other treatments and management changes, rather than as the sole therapy.

    There are multiple commercial supplements that boast a healthy serving of Omega-3 fatty acids. Flaxseed and fish oil are other sources, but beware the added calories in fat supplements, particularly in horses that are already overweight.

    Other treatments for hives, depending on the severity, include steroids, antihistamines, and desensitization ("allergy shots," selected after appropriate testing based on either response to intradermal injection of allergens or assessment of the serum). Preventative measures include fly control, fly sheets, and avoiding potential contact triggers, such as irritating pasture plants or various topical sprays. Some horses, like some people, are just more sensitive than others. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  3. At what point should I consider that my horse has developed chronic colic and what types of diagnostic techniques or expertise should I be looking for? Our local veterinarian has treated my 10-year-old OTTB mare twice in the past 12 months (tubing and IV's once, and just tubing second time). We suspect it to be sand colic, both times in the fall. She also colicked once in between these two incidents in the spring when she had been out on lush grass for a few hours a day, but easily resolved with Banamine and her removal from grass. I'm told by her prior owners that she never colicked with them. I have had her two years at the same property before she colicked the first time. I am doing everything recommended as she is on 24-hour turnout with free choice hay and a ration balancer. While she is worked lightly almost daily, it's low stress varied pleasure riding rather than performance training. (View Answer)

    Simply put, chronic colic refers to repeated bouts of abdominal pain of variable intensity. There are many potential causes to consider; I will try to briefly summarize below.

    As you mention, sand colic is one potential cause of chronic, low-grade colic, especially for horses located in sandy climates or fed off of the ground. Sand accumulates in the colon and causes irritation; it may also interfere with gastrointestinal motility and potentially lead to secondary impactions or displacements. Examination of the stool (dissolving a manure sample to look for sand granules), radiographs of the colon, abdominal ultrasonography, and carefully listening with a stethoscope can help to rule in or rule out sand colic. Empiric treatment with psyllium and mineral oil is recommended if sand colic is suspected, and management changes should be instituted to decrease sand consumption.

    Similar to sand colic, enteroliths ("stones" of mineral in the colon, originating from some nidus of irritation) can cause recurrent colic; these can sometimes be diagnosed by rectal palpation or radiographs, but at other times, they are only found during surgery.

    It's also important to consider the health of the whole horse when searching for a cause for recurrent colic. Dental disease can cause horses to chew their food imperfectly, which can lead to impaction colic. Therefore, oral examination and floating, if indicated, would be recommended. Even if the teeth are in good condition, coarse feedstuffs like coastal hay can lead to impaction.

    Gastric ulcers are another relatively common cause of chronic colic. It sounds like your horse is already managed in a way to minimize ulcer risk (lots of turnout and free choice forage, and no stressful riding), but the only way to definitively diagnose ulcers is via gastroscopy. I have seen some horses that lived fairly low-stress lifestyles, but still had severe ulcers; individual susceptibility varies. Often horses with ulcers will show other clinical signs, including weight loss, unthriftiness, "girthy" behavior, and a preference for hay over grain, but this is not consistent. Horses can also get ulcers in their colon (right dorsal colitis), particularly if they have been on a long-term course of non-steroidal anti-inflammatory drugs like Bute. Ultrasonography can help diagnose this condition.

    Parasites can also cause repeated colic. I would recommend having a fecal egg count performed to check your mare's parasite shedding status and target dewormer appropriately. Since tapeworms don't usually show up on fecal egg counts, many veterinarians recommend treating for tapeworms annually, using a product called praziquantel (which is found in Quest Plus, Zimectrin Gold, and Equimax). Incidentally, there is a new saliva-based assay to test for tapeworms that should become available in the US soon; this may help us improve our deworming practices further.

    You note that one episode of colic occurred after exposure to lush grass. The digestive process produces a lot of gas, which can cause abdominal pain, just like in humans, particularly if the horse is not used to such a diet. Exposure to new feedstuffs should allow for gradual acclimatization. 

    Other, less common causes of recurrent colic include anatomical variations, chronic bowel displacement, intestinal adhesions (arising from previous inflammation), tumors or masses within the abdomen, or inflammatory bowel disease. In each case, your veterinarian's clinical examination findings, including rectal palpation, along with additional diagnostics like ultrasonography and blood work, can help point toward an answer. In some cases, abdominocentesis ("belly tap") or biopsy of the intestines may be recommended. However, despite our best efforts, sometimes only surgery (or, in unfortunate and very severe cases, necropsy) can definitively diagnose the cause of colic. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  4. I have a rescue horse that is about 5-years-old and is said to have been gelded. There are no visual testicles, but wonder if everything was removed since he has displayed highly aggressive behavior to my mare and gelding. It began after he had been on the property for several days, I moved him so he could go nose to nose with my other two horses, one of which is a mare. Unfortunately, though it was much later in the season, my mare came into heat very hard. He began chasing my gelding away and rearing behind my mare as if he were trying to mount. She, though in heat, very much disapproved, fortunately. The former owner says the horse was gelded and that both testicles were removed. However, I wonder, is there any other tissues that should have been removed, were left behind producing testosterone? I'm having the blood work done to evaluate his hormone levels. While we wait, I started to wonder if, perhaps, tissues other than testicles can cause the horse to act studish. (View Answer)

    There is a common old wives' tale about the "proud cut" gelding, that has had his testicles removed, but retains a portion of his epididymis (the highly coiled organ that stores sperm). However, the epididymis does not produce testosterone, so even if it were accidentally left behind at the time of castration, it would not cause "studdy" behavior, and the horse would be infertile following the eventual death of the residual sperm cells (it's worth noting that even after routine castration, horses can continue to sire foals for up to six weeks, as some semen remains in the accessory sex glands).

    The hormone testing you are pursuing should tell you whether your horse has a retained testicle (cryptorchidism). The testicles in some horses do not descend into the scrotum, and because surgery can be involved and expensive, these horses are sometimes passed off as geldings by unscrupulous individuals, even though they are not. Other times, one testicle is dropped (and subsequently removed) while the other is retained. These stallions are usually infertile, but they exhibit behavior like intact stallions, as their testosterone level remains high. Additionally, the retained testicle is predisposed to becoming cancerous unless it is surgically removed.

    The most common hormone testing includes baseline testosterone levels, testosterone levels following stimulation with a hormone called human chorionic gonadotropin, estrone sulfate levels, or measurement of anti-Mullerian hormone, a product produced exclusively by the testes (and the most reliable test). If these results indicate the presence of testicular tissue, your veterinarian will likely recommend abdominal ultrasonography and/or exploratory surgery to locate and remove the source.

    In other species, adrenal or brain tumors can cause aggressive or inappropriate behavior. While a possibility, I would think this is extremely unlikely in your horse's situation. More likely, he is exhibiting learned behavior. He may just be a very dominant and aggressive horse, or he may have been bred before or gelded later in life. Stress and insecurity can also lead to "acting out." Regardless, for the safety of yourself and your other horses, I would recommend exercising caution and consulting a trainer or behaviorist to help get to the root of his problem. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  5. Are ponies more susceptible to founder than horses? I ask because I give my horses a grain supplement in the winter, along with hay, and I wonder if should provide this supplement for the pony. (View Answer)

    The short answer to your question is yes: ponies are more susceptible to founder than horses. The long answer is a lot more complicated!

    Most horses, if they are currently in adequate or overweight body condition, and if they are not in hard athletic work, will do well on a ration balancer and access to forage (hay/grass). I like ration balancers because they pack all of the essential vitamins and minerals into a compact volume, without adding a lot of calories. It is important to feed them according to the directions on the bag, rather than overfeeding. Many horses truly do not need grain, although performance horses and seniors are more likely to need the extra calories and energy. In the winter, additional hay can provide needed calories and "warmth."

    Laminitis (inflammation of the internal structures of the hoof) can lead to founder (sinking or rotation of the coffin bone), which can be debilitating and life-threatening. Laminitis can develop from myriad causes, including infection, toxins, overwork, and grain overload. Perhaps the most common cause is endocrine in origin, however.

    We still do not understand the exact pathway that leads to laminitis and founder, but it involves elevations in insulin levels, triggered at least in part by sugary diet high in non-structural carbohydrates, which includes both lush pasture grass and many commercial grains, particularly sweet feed. Two conditions in equines predispose to excessive insulin secretion: Equine Metabolic Syndrome (EMS) and Pituitary Pars Intermedia Dysfunction (PPID or "Cushing's Disease"). Ponies are affected by EMS and PPID at higher rates than full-sized horses, and they are also more likely to be obese in general, which contributes to the problem.

    I recommend that all owners of ponies keep their animals at a reasonable weight, although it can be hard to keep a pony fit and trim! Minimizing pasture access (by using a grazing muzzle or spending time in a dry lot) can help, and exercise is ideal (and can actually help reverse insulin resistance). As stated earlier, most ponies probably don't need a lot of grain in their diet, unless they have a specific health condition that calls for it. Stay on top of your pony's farrier care, and ask your veterinarian whether testing for EMS or PPID is recommended. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  6. My 11-year-old Tennessee Walking horse is switching his hind legs back and forth sometimes standing semi-parked out while grazing. He even cocks his hind leg when he grazes switching from one to the other. He was very malnourished and socially awkward when I got him a little over a month ago, but has since acclimated with my three other geldings. He is currently fed Purina with amplify and turned out on pasture 24/7. He is also offered alfalfa hay. My veterinarian said he needed about another 100 pounds. I have had my veterinarian examine his teeth, perform a lameness exam (no sign of lameness), fecal and Coggins. I have ridden him lightly and was told to condition him, but work lightly as he was probably weak due from the loss of muscle mass. We are rechecking in a month. When I do ride him, his gaits are wonderful, he does not refuse or act out. However, backing is a project as he will do what you ask, but with attitude. However, on the ground, he backs perfectly without hesitation or attitude. Should I be concerned? (View Answer)

    What you describe could have numerous causes, and it sounds like your veterinarian has already investigated many of them, but I will go ahead and provide a list of some of my differentials. A normal horse will selectively rest first one and then the other hind leg, using a special "locking" mechanism within the stifle joint. However, there is usually not a rapid back-and-forth shifting action, and from your description it appears that your gelding's behavior is different from that of your other horses.

    The first thing to consider is pain stemming from the hind legs. Stifle injuries or abnormalities can interfere with a horse's ability to "lock" his leg at rest, which can lead to shifting of weight. Weight-shifting lameness is also often associated with bilateral foot pain, such as from laminitis, although this would commonly affect the front legs more severely. Suspensory ligament injury or breakdown can occur on both hind limbs, making weight-bearing painful and causing similar shifting behavior. In each case, however, I would expect lameness and abnormalities on your veterinarian's physical examination.

    Back or pelvic pain can also cause a horse to camp out, and may not present as typical lameness (but the horse may be resentful or sour under saddle). However, I would not generally expect this to cause weight-shifting, and your veterinarian should be able to determine if your horse's back is sore. In uncommon cases, abdominal (organ) pain can lead to camping out, but this does not sound like the case with your horse.

    Neurologic disease, such as Equine Protozoal Myeloencephalitis (EPM) or Cervical Vertebral Stenotic Myelopathy ("Wobblers Disease") can lead to weakness, abnormal posture/gait, muscle atrophy, and weight loss. A veterinary exam should be able to rule out ataxia (incoordination) stemming from neurologic disease.

    Poor condition alone, as your veterinarian noted, can also cause weakness, so it will be interesting to see if the behavior stops once your horse is in better shape.

    Finally, we can consider that this may simply be behavioral or related to conformation. Tennessee Walking Horses are often taught to "park out" for showing, so this could be learned behavior. This breed also tends to have a lanky build with longer hind legs and "sickle-hocked" conformation, so this could also be a contributing factor. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  7. My boarding facility keeps our horses on lush pastures almost year round (our weather is mild here) for at least five hours/day. All of my horses are fat and the older ones become gassy with hay bellies and a diminished top line. Almost all pellets and hay are grass based. Am I unreasonable to expect a lysine source? How much lysine is needed for a 1300 lb. aged horse? My horse does not like the planted clover patches, which I understand is odd. (View Answer)

    Whether your horses’ amino acid requirements are being met by their current diet will depend on the quality and consistency of the available forage, as well as the constitution of the pelleted ration. Are the pellets fortified with any vitamins, minerals, or amino acids? Having your hay tested may also provide additional information about its nutritional content.

    I am not aware of any studies or publications specifically dictating the ideal amount of lysine to feed to a horse such as you have described. I did find one paper (Yoshiyuki et al. 2007) citing that the lysine requirement for adult Thoroughbreds is 0.47% of the diet, but this is hardly a practical measurement when there are so many unknowns in the current feeding situation.

    If the diet is inadequate and imbalanced (and it’s hard to say if it is, as there are multiple causes for poor top lines), I would be concerned that the horses may be missing more than lysine, although this is considered the most “rate-limiting” amino acid, forming the building blocks of proteins. Rather than specifically supplementing for this one component, I’d be inclined to put your horses on something that’s fortified with multiple elements. Most commercial horse feeds have added lysine (among other necessary nutrients) to ensure that a horse’s dietary needs are met. This requires that the feed is provided to the horse in the quantity dictated by the label directions. A good feed can certainly make up for deficiencies in the pasture or hay supply, but most horses don’t need a lot of grain. For this reason, I am a fan of ration balancers, because they pack a lot of vital nutrients in a small package without a lot of added bulk or calories. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  8. I have a 14-year-old stallion that is behaving fine with normal bowel movements with some gas. However, when I touch either of his sides he pins his ears and turns his head as if he is going to bite me but never has. Should I be concerned? (View Answer)

    Without observing your stallion’s behavior and examining him in person, it is difficult for me to determine what may be going on. Touchiness around the sides can be a symptom of gastrointestinal discomfort (ulcers, etc.), musculoskeletal soreness, or just being a grouch that doesn’t like people in his personal space. The fact that he is offering to bite you concerns me that this may become a dangerous behavior, and I would certainly recommend being cautious around him. A veterinary examination should be able to help you rule out physical discomfort; depending on the findings, blood work or further diagnostics may be recommended. If there does not appear to be a physical cause for his behavior, you might be better off working with a trainer to address his grumpiness and potential aggression. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  9. I have heard of how bovine colostrum is very supportive to horses health. I would like to try it but I don't know how much of it to feed and how often. I am only able to give it in liquid form, so it would be helpful to get a measurement in ounces. Could you give me a recommendation for horses around 1,000-1,200 pounds? (View Answer)

    Colostrum is the "first milk" produced by a mother to nourish her offspring. Unlike the milk that is produced throughout the majority of lactation, colostrum is rich in antibodies and immune-boosting factors. For animals like cattle and horses, colostrum is the primary source of infection-fighting power during the first few months of life, when the immune system is immature. In fact, colostrum is so vitally important to newborn foals that we routinely perform a blood test (measuring IgG levels) when they are a day of age to ensure that they have ingested enough colostrum and do not have "failure of passive transfer" (that is, to make sure antibodies to ward off infection have been transferred from the dam to the baby). If inadequate immunoglobulin levels are found, we will give an intravenous infusion of equine plasma to the new foal to help boost its immunity and to minimize the risk of infection or sepsis.

    Why do we usually give plasma to newborn foals instead of just colostrum? Well, for one thing, equine colostrum can be hard to come across, and colostrum from other species just doesn't have the same effect (the majority of the proteins and beneficial element are species-specific). For another, once a foal has ingested milk, and certainly within 24 hours of birth, its gut is making a remarkable transformation. The neonate is born with a "leaky" gut, meaning it permits absorption of large molecules, including immunoglobulins from colostrum. It makes a rapid change after birth to essentially close off to larger molecules, which helps keep the foal from ingesting and absorbing harmful things, such as bacteria. It also means that immune products from colostrum are no longer absorbed or beneficial after a day of age.

    With this in mind, I have a hard time understanding the purported benefits of administering bovine colostrum to adult horses. They certainly will not be systemically absorbing or benefiting from the immunoglobulins. I suppose there is a possibility that said immunoglobulins might have a mild anti-inflammatory effect within the gastrointestinal system, but this is purely speculation on my part and I am not aware of any studies to this effect; rather, it would seem that digestive enzymes would rapidly break down the majority of these proteins. Colostrum does have a significant fat and protein content, which could potentially help a horse with weight gain or other issues, but there are cheaper and easier ways to achieve this in the diet using feeds and supplements specifically formulated for horses, often to address a specific health issue.

    I found one paper (Fenger et al. 2016) evaluating supplementation with an enhanced product containing bovine colostrum along with multiple vitamins, minerals, and other agents; in this study, modest decreases in the duration of respiratory disease were noted. However, the researchers did not examine the effects of colostrum by itself (making it impossible to determine which part of the supplement was responsible for the benefits), and the results were not dramatic. Until further studies validating the benefits of bovine colostrum have been performed, I cannot recommend its use in horses. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  10. A local barn (Waterford,CA) is advising that all boarders vaccinate for Pigeon Fever. Is there a vaccination to prevent Pigeon Fever? This is the first I have heard of this. (View Answer)

    "Pigeon fever" got its name because the most common form of the disease involves swelling and abscessation of the pectoral region, which resembles a pigeon's breast. The disease is not caused or carried by birds, but instead is the result of infection with a bacterium called Corynebacterium pseudotuberculosis. This pathogen and related forms can also affect other animals, including sheep and cattle, but the syndrome in horses is fairly unique to this species. It is most common in arid climates, but can be found all throughout the United States, and its prevalence is increasing.

    There are three forms of pigeon fever. The first is the most classic: the aforementioned abscesses in the chest (and potentially elsewhere on the body). While this can be painful and unsightly, most horses make a full recovery. The abscesses may be lanced and drain to facilitate healing, and the horse may be put on anti-inflammatory medications, but antibiotics are rarely indicated. In a more severe (but thankfully less common) form of pigeon fever, abscesses form internally, potentially including the lungs and abdomen. While initial signs of a problem may be subtle, eventually these horses become very ill, and diagnostic tests (including blood work, ultrasonography, and more) may be needed to pinpoint the problem. Internal abscesses can be life-threatening, and require aggressive and prolonged antibiotic therapy to provide a reasonable chance of successful treatment. The final (and rarest) form of pigeon fever is called ulcerative lymphangitis; here, the bacteria travel through the circulatory system and form multiple small, draining abscesses throughout the vessels, usually concentrated on the limbs. Cellulitis (bacterial infection and inflammation under the skin) results, and the horse is febrile and extremely lame. Again, aggressive treatment with antibiotics and anti-inflammatories is indicated.

    Currently, there is no equine vaccine for C. pseudotuberculosis. A vaccine was briefly available a couple of years ago, but was soon pulled from the market after some treated horses developed significant gastrointestinal side effects. I am not aware of any plans for a new pigeon fever vaccine to hit the market anytime soon. While there is a goat vaccine for C. pseudotuberculosis, the variant of bacterium is different in small ruminants versus horses, and this vaccine is not validated in or approved for equines. Therefore, prevention revolves around prompt recognition of the disease, so that affected horses can be isolated and treated.

    The bacterium can live for prolonged periods of time in soil. Additionally, flies and insects are a major source of transmission between horses (bugs feed on the pus from draining abscesses, either on the horse or after it drips onto the ground, and then bite another horse, thereby inoculating infectious bacteria). Horses affected by external abscesses should be quarantined, and their living quarters should be thoroughly disinfected before allowing other horses into the area. Abscesses should be drained and flushed by a veterinarian once they mature, as well, as this can help to contain the infectious pus, rather than contaminating the environment. Fly control measures are also important: utilizing such things as fly spray, parasitic wasps, fans, fly tape/traps, and more.

    Prompt recognition and treatment of disease provides the best chance of limiting the spread of infection and ensuring the horse makes a full recovery. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  11. When a horse leaves our rescue facility for training with an approved trainer, is it necessary to return that horse to quarantine before returning him to the rest of the equine population? We do not know what best practice is in this case. Our operation is a horse rescue located in Edgewood, New Mexico. (View Answer)

    Ideally, whenever horses are commingled with a new population, they would be isolated upon return to ensure they do not bring any pathogens back to their buddies at home. What constitutes best practice is not always the most practical advice, admittedly, but it is certainly easier to prevent an outbreak of disease versus deal with the potentially catastrophic aftermath!

    When bringing in a new horse, or bringing back an old one, a 14-day quarantine is a good guideline. Keep the horse physically separated from the rest of the herd, far enough away that wind cannot carry potentially infectious respiratory droplets to the other animals. Have barn help feed and care for the new horse last, and wash their hands in between groups of horses. Take the new horse’s temperature twice daily to ensure there is no fever; if any signs of illness are noted, significantly greater care will need to be taken as part of the biocontainment protocol (strict isolation, disinfection, etc.).

    While it sounds like your horses are going to well-managed training operations, training is a stressful experience for a horse, and this increases the risk of respiratory disease, especially when multiple young horses are brought together from diverse sources. Most respiratory viruses have a relatively short incubation period, but some, like Equine Herpesvirus, maintain lifelong infection, so that a horse can become a potentially contagious “shedder” whenever he is stressed again—such as after a move. Other diseases, like Strangles, can be transmitted by inapparent carriers. A horse is relatively unlikely to pick up Strangles at a training barn if there are no horses showing signs of clinical disease, but since you have a rescue operation (presumably with horses coming from some questionable circumstances), I would recommend a Strangles PCR test whenever you add a truly new horse to your herd, even if it appears outwardly healthy during quarantine. This is especially important for horses coming from auctions and feedlots.

    Finally, you can minimize the risk of an infectious disease outbreak by ensuring your resident horses are up to date on their vaccinations and by using common sense when it comes to isolating and treating any sick horses. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  12. I have heard that if you give the West Nile vaccine to stallions that it can make them sterile. Is this true? I want to give the vaccine to him but do not want to cause him to become sterile as I breed him every year. (View Answer)

    I would definitely recommend vaccinating your horse, as there have been multiple reports of equines becoming ill with, and even dying from, West Nile virus this year. Fortunately, the West Nile vaccine is safe and has no association with sterility in stallions. 

    With any vaccine, there is always a small risk of a reaction. If a stallion develops a fever (due to vaccine reaction or other cause), it may temporarily decrease his fertility by damaging the developing sperm cells. Therefore, it is best to vaccinate 60 days prior to the breeding seasons, both to maximize immunity and to minimize the risk of complications. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  13. I clipped my horse (28-year-old Morgan mare with PPID and IR, that has a very thick winter coat) along the ventral neck and the anterior part of her shoulders as she sweats a lot there. However, here we are located in Georgia and there are cold days. What is the best way to blanket her, if at all? I want to keep the hairless parts warm but the rest of her body usually needs nothing in the winter. (View Answer)

    It sounds like you are a very conscientious and devoted owner who is pretty in tune with your mare's needs. As you know, horses with PPID have trouble regulating their body temperature, and they can be especially sensitive to both cold and heat. Since you have already clipped part of her coat (and it sounds like it was in her best interest to do so), you'll definitely want to protect these areas from the cold, and your best bet may be to clip more of her body and blanket her wherever it is chilly. Leaving the longer haircoat under a blanket impairs thermoregulation and could certainly make her too warm in spots, plus it may trap sweat and moisture, creating an uncomfortable situation. Unfortunately, no one has yet invented a blanket that just covers the ventral neck and shoulders! Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  14. I have a 28-year-old Morgan mare with PPID and IR. She had several months off at the beginning of the year and lost condition. We have been riding her now inconsistently (due to my work schedule) since April and she is definitely looking better (top line, general muscle, etc). However, we want to do better by her. What is a good regimen to get a horse like her back in decent shape? We ride English and love to event. She will still jump small cross rails etc. She is active, but I don't know what is okay to ask her to do as my daughter and I are afraid to ask too much of her. Should she be on a supplement to support this kind of activity? (View Answer)

    Kudos to you for your concerns about keeping your horse fit and healthy in her geriatric years!

    First, is your mare being treated for her PPID? Pergolide would definitely be on the top of my list of treatments, if she is not already receiving it.

    At her age, arthritis is a real possibility. There is very limited evidence to support the use of nutraceuticals for the management of osteoarthritis, but some owners do report seeing positive changes when feeding a joint supplement or omega-3 fatty acids. Feeds or supplements containing higher levels of protein/amino acids can help support top line development. However, any excess source of sugar/calories, or any medications containing steroids (including joint injections, in the case of lameness localizable to a specific joint), should be used with caution in insulin resistant horses.

    Has your mare ever been affected by laminitis? If so, this could be a performance-limiting factor for her, but her comfort level and soundness should tell you how well she can hold up to the work she is asked to perform. As long as she seems willing, happy, and comfortable, I think it is fine to continue using her as you describe. As an added bonus, exercise can help older horses stay fit, healthy, and moving well, and exercise can even help to reverse insulin resistance.

    When it comes to conditioning her, assuming she is sound, I would treat her like any other horse: start slow and gradually increase the work duration and intensity. Low level consistent work is safer and better than periodic high intensity work. Pay close attention to her behavior, soundness, and recovery (sweating, respiration, etc.) post exercise. I believe she will tell you whether she is able to hold up to what is asked of her. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  15. If my horse is doing well on free choice hay with some alfalfa and supplement, is there any reason to change his feed during the cold weather? (View Answer)

    If your horse maintains a good body weight throughout the winter, I see no reason to supplement beyond the provisions you have described. Free choice hay provides a great source of forage. This is broken down in the hind gut by microbial fermentation, which generates heat and warms the horse. Horses do have additional energy (caloric) requirements in cold conditions, but these can usually be met by quality hay. For horses that are average to overweight, I recommend supplementing the hay with a ration balancer to ensure that the essential vitamins and minerals are being consumed. If the horse is underweight despite free choice hay, I would add some other form of grain or concentrate as an extra source of calories. As always, ensure your horse is drinking enough (make sure his water source is not frozen over); some horses are reluctant to drink cold water, especially when the weather is chilly. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

  16. I have an almost 18-year-old Paint mare that has soft soles. The farrier has known her and trimmed/shod her her whole life. I have just recently purchased her as a pleasure horse (occasional riding). I am trying to decide if I just should keep her shod or if I can approach it from another angle, e.g. farriers formula supplements, boots for when I ride until the soles toughen up slightly, etc. The farrier says she is the best she has ever been, so the environment is ideal. But what more can I do to help her, if anything? (View Answer)

    Your question is a good one, but you have already pretty well answered it yourself! I think all of the things you mention are reasonable to try, and your farrier (and your mare’s response to his adjustments) will tell you how to proceed.

    Many horses do very well barefoot, but others are genetically or conformationally predisposed to having bad feet, for a variety of reasons. Proper nutrition can help to encourage adequate hoof growth, and supplementation with biotin seems especially beneficial (of course, it is important to ensure that the horse’s overall diet is balanced and contains all essential vitamins/minerals, as any deficiency thereof can manifest as hoof abnormalities).

    Sometimes shoeing a horse with a pad can help to encourage sole growth; with time, the pad (and potentially even the shoe) can be removed. Using specially designed hoof boots on an otherwise barefoot horse, either when riding or full time, can serve some of the same purpose, but will primarily help to protect and cushion the sole from hard ground, preventing bruising.

    If the primary issue is soft soles, as opposed to very thin soles, topical treatment can sometimes help to “harden things up.” Talk to your veterinarian and farrier about whether “sole paint” is appropriate for your horse.

    You may also consider having radiographs performed to assess sole depth and to measure the angles of the joints within the hoof, as these things can also contribute to foot soreness. Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri