Revised:  01/10/2013

Ask the Expert -- Equine  Management













Equine Management

Diseases and Disorders






My horse’s hind leg locks up. Could it be an abnormally locking patella?


My horse’s back leg sometimes gets so stiff that when he walks he looks like a person trying to walk with a cast on one leg. Why is this?




This sounds like a horse with an abnormally locking patella (knee) or “intermittent upward patellar fixation”. There are three ligaments that go around the patella in the stifle of the horse (the joint above the hock in the hind leg, similar to a human knee). These ligaments around the patella are used to lock the horse’s leg in place so they can sleep standing up. Usually the locking mechanism can unlock itself very rapidly when needed, e.g. if the horse spooks. However, sometimes there is a problem where the lock gets stuck and the horse will be unable to move its leg for a period of time.

A horse's stifle joint as seen from the front.

There are three main causes of this locking problem: 1) a horse that is unfit might not have enough muscle tone in its hind limbs to trigger the unlocking response, 2) horses with unusually upright hind limb confirmation are more prone to abnormal fixation, and 3) some horses have ligaments that are longer than average, so the locking mechanism gets stuck more easily in them than in most individuals.


Given these reasons, there are several ways to go about correcting the problem:

  • Exercise - horses that are unfit will benefit from strengthening of the hind limb muscles. Increasing fitness of the horse will also help increase the effectiveness of other treatments.
  • Corrective shoeing - shortening the extension phase of a stride will lessen the likelihood of the mechanism getting stuck. Use a rocker shoe, or roll the toe. Egg bar shoes or wedge pads are commonly used.
  • Hormonal therapy - estrogen has been found to help these horses. This will help tighten the ligaments that cause the problem.
  • Blistering - infusing an irritant into the joint to create scar tissue to inhibit the locking mechanism in the joint. This is not generally recommended, but could be useful in severe cases.
  • Ligament resection - last resort and is not generally recommended.

Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.


Can a horse with anhydrosis (lack of sweating) still be ridden?

My horse, a 22-yr. old Arab, has recovered rather well after founder and a few nasty abscesses. We’re back to a regular exercise program, but recently, during a stretch of very hot and humid weather, he lost the ability to sweat, and at the same time, showed signs of dehydration. I have started him on a supplement designed specifically for this condition. Could you please describe anhydrosis? Can anhydrotic horses be worked as long as they are cooled down properly? Is it a good idea to give them electrolytes, or not?


Anhydrosis – the absence of the ability to sweat – is a big problem in all disciplines. However, it is more prevalent with endurance-type horses. Supplementation with an electrolyte replacement after the horse has worked hard will also help. Unfortunately, not much is known about how to prevent the condition. There is only one other supplement that is proven to help decrease the severity and incidence of anhydrosis; just do an online search for “anhydrosis supplement” and it will pop up.


As for your specific question, horses that do not sweat can still be ridden. Just be careful not to overdo it. If you are too hot and miserable to enjoy the ride, he will probably be as well.


It is extremely critical that you take care in the cooling out process and monitor your horse’s vital signs. Lots of shade and ventilation are necessary when cooling anhydrotic horses out. Hosing under the belly, chest and between the legs is also crucial.


More information on horses undergoing heat stress is available in our fact sheet on stress; it covers a bit on anhydrosis as well.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.


Can antibiotics cause loose stool?

My 16-yr old Quarter Horse mare has a runny, snotty nose, a temperature of 100.5, and her appetite is a little off. Her runny nose got worse over a 3-day period. My vet put her on an antibiotic for a couple of days. I mixed the medicine with feed and corn oil to make it stick together. She is eating better today, but has loose stools. Do I need to worry about the loose stools? Is the medicine causing them?



Antibiotics can cause loose stool. They kill the bad bacteria causing the sickness, but also kill good bacteria that are used in the digestive process of the horse. It is sometimes recommended to feed a probiotic along with the antibiotic to help replace the good bacteria that are being killed by the antibiotics. You can continue the probiotics after the antibiotics are finished and monitor the stool. Over the course of a week or so the stool should get back to normal and the probiotics can be discontinued. If the stool does not get back to normal you should consult with your veterinarian. However, if a horse is under veterinary care and its condition changes such that it develops new clinical signs (develops diarrhea) the veterinarian should be made aware of the situation. While antibiotics can cause diarrhea, the diarrhea may also be a sign of a progression of the horse’s illness and the horse may need more than a probiotic.


Answer provided by Carey Williams, Ph.D., Equine Extension Specialist, Rutgers Cooperative Extension and reviewed by Shari C. Silverman V.M.D., Senior Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.



How do I treat my horse for asymptomatic Lyme Disease ?

My horse was just diagnosed with Lyme disease. I had it tested in order to get a baseline, now that the new advanced three-tier titer test from Cornell University is available. Much to my surprise, the horse’s OspF level is over 4,000, indicating that it has a chronic infection. However, the horse shows no symptoms of disease. Is it possible that the horse will never develop symptoms or do I have a short window to treat this before active disease develops? If the latter, would you treat with IV Tetracycline or oral doses of Doxycycline?



Many animals, large and small, diagnosed with Lyme disease exhibit no clinical signs. Animals and people with healthy immune systems have the ability to clear the infection. In fact, if you test anyone who has been exposed to ticks they probably would test positive for Lyme disease. Which brings me to the question as to why you tested the horse for Lyme disease if it did not display any clinical signs? Horses can demonstrate depression, lethargy, exercise intolerance, lameness, joint swelling, fever, etc. for many other reasons than Lyme disease.


There are two view points in the veterinary profession: 1) treat the clinical signs; or 2) treat the laboratory findings. So if one decides to treat the animal, it always helps to have some goal in mind to reach so that improvement can be identified. If the horse displays clinical signs, then after a successful treatment, improvement should be seen. The same applies to findings from the blood work. Unfortunately in my experience, I have not changed much blood work findings for Lyme disease with the treatment. But you should discuss this with your veterinarian. Your veterinarian can also speak with scientists at Cornell regarding their experience with blood work “improvement” after a course of treatment. Cornell does have a good test which can help identify horses that had previous exposure, current infection, or vaccination exposure.


As for the type of treatment that is the best, the current consensus is that oral or IV administration does not make a difference.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



My horse appears to have blocked airflow; is this a problem?

I have a 24 year old American Saddlebred mare. I ride her almost every day, either indoors or on a trail. I turn her out in the arena after riding her so
she could roll and relax a bit before going back to her stall. In the cold I could see that the "steam" coming out of one nostril was much fuller and blew-out further than from the other nostril. She has had rare incidences of bleeding from the nostril that appeared to be somewhat blocked in airflow. I wonder what you make of this. She is bright in affect and in good health overall. Once in awhile she will have slight discharge from the same nostril or both. I feel she is in great health for a mare her age but could this air flow be a problem going forward?



Several conditions occur in horses that have the potential to partially or
completely obstruct a nasal passage. Typically these conditions are accompanied by additional clinical signs like exercise intolerance, shortness of breath, nasal discharge, bleeding, etc. I’m not sure that evaluation the steam coming from both nostrils is the most sensitive indicator of a problem with your mare. There are other diagnostics that you can pursue if you do believe that a problem exists. Your veterinarian can perform x-rays of the skull and or perform an endoscopy of the air passage. An endoscopy is a small camera on a fiber-optic tube that is placed up the nose. This provides direct visualization of the nasal passages all the way to the beginning of the lungs. If there were an obstruction, it would be detected with this test. At this point, it would probably be best to address your concerns directly with your veterinarian to determine if these other diagnostics are reasonable at this time.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University and approved by Nancy E Halpern, DVM, Director, Division of Animal Health, New Jersey State Veterinarian, New Jersey Department of Agriculture.



What can I do about a horse with capped elbows?

I have a 17 year old gelding that has capped elbows and the veterinarian said they are not a problem. They don’t cause him pain; they are just there. I have used a doughnut boot, but it didn’t change anything. However, lately I’ve noticed the area has become very dry and the skin is flaking off. It is in a difficult area to reach and hard to curry; but, even when I do, it just comes right back. Is there anything you might suggest to help get rid of the dry skin?



Capped elbows can be a real problem to deal with, especially if they keep coming back. Using doughnut boots is a great start. Try applying baby oil or another type of skin softening product to the elbows to help with the dry skin. One common product is udder balm; it is a thick cream/gel similar to petroleum jelly, but actually has properties to help heal the skin. This may be a good option because it would not need to be applied as often as the baby oil.




How can I control my horse's Cellulitis (Lymphangitis)?

I recently bought a nine year old Quarter Horse gelding that has had bouts with cellulitis in the past. The last time its leg swelled up, I called the veterinarian and followed the directions: cold hosing twice a day, hand walking, using a sweat wrap at night, and standing wraps during the day. The horse is also on an antibiotic in pill form; although, I have not had much success administering these as it will not eat its feed and is very adept at avoiding the syringe. Fortunately the swelling went down and its leg was only a little warm around the pastern. I understand I need to make sure its legs are clean and dry whenever the horse is turned out. Are there any supplements I can give to help boost the immune system in order to deal with this? What is the best thing to use on the horse’s legs and how often should it be applied?



Congratulations on being a horse owner and welcome to the world of moderately intensive management. Cellulitis is a condition of cellular inflammation. It usually involves the subcutaneous (under the skin) tissues and can be extremely painful. It can look very similar, if not identical, to lymphangitis (inflammation of the lymphatic system of the leg).


Your horse may be extremely susceptible to getting swollen legs which presents a clinical problem. You are not alone, many horses and owners deal with this condition. Old lacerations, infections, or injuries may predispose horses to develop this condition. In addition, the environment can also play a factor. Some horses may have never had cellulitis, yet as soon as they move to a new farm, they get it routinely.


Consult your veterinarian as to the appropriate treatment and prevention for your horse. Prevention, however, is the best treatment. Keep legs clipped, cleaned and dry. At the first sign of a swollen limb, immediately clean the legs and apply pressure wraps or even sweat wraps (such as alcohol or Epsom salt/furacin). Sometimes poultices can be helpful. It is important to keep these horses moving to promote blood flow (venous and lymphatic return) through the limb. They should not be confined to stalls unless absolutely necessary. When these measures are not enough, consider anti-inflammatory and antibiotic treatments. This must be prescribed by your veterinarian.


With respect to your horse not letting you administer the medications, like a child, they don’t like the medication. There are safe and effective ways of administering medication that your veterinarian can provide. Another trick is to mix the medication with something the horse likes, such as applesauce, in the dose syringe or giving it a treat like a slice of apple or “horse cookie” immediately after giving the medication to make it a more pleasant experience. It is important that your horse receive the medications, so the job must get done.


Unfortunately there is no magic cure for the condition and no immune system booster to help. A vigilant owner must monitor their horse closely and treat aggressively with the first sign of a reoccurrence.



This answer was written with the help of Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University and approved by Nancy E Halpern, DVM, Director, Division of Animal Health, New Jersey State Veterinarian, New Jersey Department of Agriculture.



How can I manage a chronic sinus infection?

My horse has suffered from sinusitus for ten years. The sinusitus was caused by a fractured tooth which resulted in the tooth being removed and an operation to scrape and flush the sinus. Since then, he has had mild discharge, occasionally becoming severe. When this occurred, he was sent away for his sinuses to be flushed again; however, it was eventually decided that the procedure was not worth doing due to the invasive, traumatic nature of the operation.

My horse has suffered from severe discharge, coughing when ridden, and difficulty breathing when ridden. My vet has treated him with antibiotics (which has helped clear the infection, evidenced by the change in the color and thickness of the discharge), however the other symptoms are still present. My horse is now 22, and at that age, I do not want to send him for further surgery. Do you have any advice on how to manage this condition, if I decide not to send him away for a further operation?



Cases of chronic sinus infections secondary to a tooth abnormality can be extremely difficult, frustrating, and costly. It is common for chronic sinus infections to be secondary to tooth root abscesses. In some situations, the horse can still have a remaining fragment of tooth root within the socket that is causing the persistent infection of the sinus. A surgeon can attempt to remove this fragment with a sinus surgery such as sinoscopy or sinus “flap” surgery to scrape out the sinus, try to remove the fragment, and clean up the socket. Some of these surgeries will be successes; however, sometimes it never completely resolves. A surgeon may recommend repeat surgery to try to resolve the issue; however, we recognize that there are financial and emotional limitations that clients have with their horses.


In this situation, the owner could consider more advanced diagnostics to isolate the problem. For instance, an MRI or a CAT scan could be useful. The disadvantage to this diagnostic would be the cost as well as general anesthesia of a 22 year old horse. The next diagnostic to consider is repeated radiographs (x-rays). Some dental specialists perform intra-oral radiographs, which requires special equipment, but provides impressive results.


If the owner decides to “maintain” the horse the best he or she can without any “heroics” or aggressive treatments, this is completely understandable. The author had a horse with a chronic sinus infection for at least 3-4 years. The horse underwent surgery and it did not resolve the issue. The horse was maintained by repeated courses of antibiotics and the periodic sinus flushing. Ultimately, the horse was put down for unrelated issues. Afterward, an extremely small tract was found that was pocketing food from the mouth into the sinus at an unrelated tooth. These cases can be very frustrating.


As for other surgical procedures, a veterinarian could repeat the sinus “flap” procedure. Recently, many surgeons have performed this procedure on the standing but sedated horse. Of course this depends on the behavior of the horse, as the veterinarian will be working with instruments around the eye, but it can be done without general anesthesia. It may not be cheaper, although veterinarians try to make it so by doing it on the standing horse. There is also a minimally invasive technique that involves making smaller holes and using cameras in the sinus. This is good for a look into the sinus, but has its limitations with regards to accessing a lesion or a fragment.




How can I manage collateral ligament strain in my horse?

My dressage horse has been diagnosed with a collateral ligament strain in its left coffin joint. The treatment prescribed was hosing, icing and wrapping the leg, hand walking for a week then returning to light work under saddle for another couple of weeks. I was told I may want to consider the IRAP (?) treatment. My concern is that there isn't enough rest for this type of injury. The horse has been off and on for the last couple of months and I want to make sure I do not create irreparable damage to the leg by returning to work too early. Can you tell me more about this type of injury?



Collateral ligament injuries have become increasingly prevalent in the last few years, mostly because we have a heightened awareness of them . They vary in their presentation, severity, and treatment options. It would be inappropriate for anyone other than the diagnosing and treating veterinarian to recommend or prescribe a treatment protocol to you for your horse. Much
of this depends on the MRI or ultrasound findings as well as the clinical lameness in the horse. Many horses which are thought to have “strained” a soft tissue structure have had nothing discernable found on the ultrasound and, after a couple weeks off, returned to work without a problem. It is recommended to monitor them closely as they return. With any minor inclination of lameness, activity should again be discontinued. Cases where there is an identifiable lesion (abnormality) on the ultrasound or MRI, are treated with extended lay-up and rehabilitation periods, with progress being evaluated by repeat diagnostics.


It is recommended that you have this discussion with your veterinarian. If you are not satisfied with your veterinarian’s explanations, seek a second opinion from a licensed veterinarian that specializes in this specific type of injury. Your best bet would be to consult your local University or College of Veterinary Medicine or your state’s Association of Equine Practitioners.


With respect to IRAP® (Interleukin-1 Receptor Agonist Protein) therapy, there have
been significant improvements in lameness and soft tissue injuries with this treatment modality. This treatment is used to counteract the inflammatory protein, Interleukin-1. It is a relatively exciting new treatment option that is being used much more frequently. Additional treatment options that can be considered are stem cells and PRP or Platelet-Rich Plasma.



This answer was written with the help of Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



What causes a horse to drool excessively?

Several questions regarding drooling horses have crossed my desk in the last month, such as:

  • What causes a horse to drool excessively?
  • Do I need to worry about the fact that it lasted all summer this year, and is still happening?
  • Should we have the field sprayed or will that cause even more problems?

“Slobbering Horse Syndrome,” “slobbers,” and “excessive drooling” are all terms for a disorder that results in the spring and summer when horses eat legume forages, particularly clover, which have been infected by the fungus Rhizoctonia leguminicola. This fungus produces an alkaloid called slaframine, which is responsible for the excessive drooling and slobbering. Slaframine stimulates the salivary glands and smooth muscles.


The fungus most commonly affects clovers (red, white, and alsike) and alfalfa, and increases when these forages become drought-stressed or are exposed to prolonged wet conditions. It forms a black patch which may be visible on the leaves of the plant, hence the common name "black patch." Pastures can vary in species composition from year to year due to environmental conditions, grazing pressure and management. White clover will increase in a pasture when conditions are favorable. If pastures are overgrazed, and the more productive cool season grasses such as timothy, brome, and orchardgrass are eliminated, white clover becomes very competitive. White clover will also increase if adequate soil fertility levels are not maintained and if warm temperatures in spring restrict the growth of cool season grasses. Change in pasture management (i.e. fertilizing, resting, and rotating pastures) can reduce the amount of white clover in a pasture. Change in environmental conditions, cool spring temperatures and drier summers with adequate rainfall will reduce the growth of the fungus on the plants. This is not a problem that occurs in all pastures every year.


Hay made from contaminated forages is also suspect, and the fungus can maintain toxicity while baled for several years. Your veterinarian or Extension agent can confirm the presence of "black patch" in your pasture or hay. Horses are most commonly affected, although cattle, sheep, goats and swine are also susceptible. Along with excessive salivation, symptoms include tearing, difficulty breathing, increased urination and feed refusal. In severe cases, diarrhea may also occur, though horses do not usually dehydrate or develop more serious health problems. It is not uncommon for some horses in a pasture to be more severely affected than others. This might be related to whether or not they prefer clover over the other forages available in the pasture or have different levels of sensitivity to the toxin. Some horses may get ulcerations and scabs on the face and areas of the legs that come in close contact with the infected clover, as an allergic reaction to the fungus in the clover.


To help eliminate salivation and skin lesions, remove horses from pastures with high clover concentrations, and begin mowing pastures until the Rhizoctonia is no longer observed on the leaves. Most cases don't require treatment, and most animals recover within a couple of days after the fungus is removed. Severe cases that do not clear up within a day or two should be seen by your veterinarian.


Clover can be suppressed by using a variety of herbicides such as Ally1. Ally is relatively safe and has no grazing restrictions. Fertilizing pastures in spring, summer (if conditions warrant pasture growth), and in fall with 40-50 pounds of nitrogen per acre will provide the grasses with a competitive advantage over the clover. If pasture grasses do not receive nitrogen fertilizer, the competitive advantage shifts to the clover, which is able to fix nitrogen and quickly take over, especially if the pastures are overgrazed.


1Before using any pesticide, always read the label. Use pesticides only at recommended rates and time. Where trade names are used, no discrimination or endorsement is implied.


Answer provided by Donna Foulk, former Senior Agriculture Program Coordinator, Rutgers Cooperative Extension, Bill Sciarappa, Rutgers Cooperative Extension Agricultural Agent, Sarah Ralston, VMD, PhD, Rutgers Cooperative Extension.  (Some information by Mark A. Crisman, DVM, “Slobber Syndrome” from “The Mane Points” website, copyright © 2001-2003)



How do I 'dry up' my mare after lactation?

I have a mare with her first foal, which is nine months of age. The foal began weaning four days ago. However, the mare has not 'dried up' yet. I understand there may be some risk with her not drying up. Is this true and if so what can I do?




The concern with a mare not drying up is that her mammary glands could become infected, which is called mastitis. Mastitis can occur up to eight weeks after weaning, which is why properly drying up a mare is important. The best way to dry up a mare is by cutting back on her feed ration and leaving the udder alone. Remove any grain from the diet and provide only pasture grass or hay with free access to water and a salt block. After a few days to a week, milk production should decrease and the grain could be SLOWLY added back to the ration but only if it is necessary to maintain body condition. Do not be tempted to remove the milk; this will only stimulate milk production and delay the drying up process. The mare will be uncomfortable for a few days to a week and should completely dry up in about a month. However, it is important to continue to check the udder for unusual heat or swelling and, if concerned, take the rectal temperature periodically to make sure there is no fever until the mare completely dries off. While mastitis in horses is uncommon, it can happen. Mares’ udders will normally be warm, swollen, and somewhat tender during the first week after weaning; however, if the heat and pain persists for 2-3 weeks, an infection might be present and veterinary care will be necessary.



Answer provided by Carey Williams, Ph.D., Rutgers NJAES Cooperative Extension



Can my horses get E. coli from cattle?

My horse is at a cattle ranch where the cows and calves were trucked to the ranch in E. coli-contaminated commercial trucks. Many calves have developed E. coli from the trucks. Some of the sick calves have been kept in the barn, along with horses. They have not had direct contact, but the horses are being used to move the cattle. The horses are used in the fields and are drinking from the same streams as the cattle. Horses are not turned out in the fields with the cattle. Does this pose a risk of contamination to the horse and to humans?




Unfortunately, your question is not an easy one to answer. E. coli is not easily transmitted across species; however it is possible. The strain of E. coli plays an instrumental role on the contagious nature of the infection, especially across species. It is recommended to discuss the specifics of the infection at this farm with the treating veterinarian. He/she may have isolated the strain and would then be able to comment on the contagious nature that has been seen with these calves and how this may affect the horses. See below for websites which have background information on E. coli infections in cattle; they also discuss the infections in horses as well as humans.


Further reading:





Why shouldn't endophyte-infected ryegrass be fed to geldings?

I understand that endophyte-infected pasture is not appropriate for broodmares, as it causes reproductive problems. However, I was wondering if it is safe to graze an all-gelding herd on endophyte-infected perennial ryegrass?




Endophyte-infected tall fescue and perennial ryegrass are completely different grasses. Perennial ryegrass, usually found in turf grass seed mixes, is infected by a different endophytic fungus than tall fescue; therefore, it has different effects on horses. Horses of either sex can be affected by a condition known as “perennial ryegrass staggers” if the ryegrass is infected by endophytes that will release a toxin under specific environmental conditions. The endophytes make grass much hardier, which is why they are commonly used in the turfgrass industry. This is also why a lawn seed mix should never be used to seed a pasture for horses or other grazing species. Turf grasses are not selected for their nutritional value or safety if consumed in large quantities.


According to the Merck Veterinary Manual, sheep, cattle, horses, farmed deer, and llamas are susceptible to ryegrass staggers. Symptoms include head nodding and tremors when the horse is at rest. If the horse becomes excited or frightened, the head nodding can become more severe and movement can seem jerky, stiff, and uncoordinated. In some cases, the horse may fall to the ground and flail for a few minutes before getting up again. The endophytic fungus also produces ergovaline, the alkaloid responsible for fescue toxicosis in mares.


Horses typically recover within one-to-two weeks of being removed from the infected pasture. The condition is generally not fatal unless the animal ends up in an unsafe situation as a result of the staggers (e.g. drowning).


It is important to note that endophyte-infected annual ryegrass can be fatal to horses and livestock. Symptoms of “annual ryegrass staggers” are similar to perennial ryegrass staggers, but the toxins are different and can cause death within hours to one week after ingestion.


Endophyte-infected tall fescue is generally safer for geldings and mares not used for breeding because it is infected with a different endophytic fungus than ryegrass. It can cause fever, rapid breathing, rough coat, excessive salivation, and lameness in all horses in rare cases, and reduced weight gain in young animals. Severity of symptoms depends on temperature, time of year, infection level, and the strain of fescue.



What are normal EPM levels in the horse?

My friend, who is in the hay business, asked me what are the normal EPM levels in a horse and how/if hay can affect those levels?




Equine Protozoal Myelitis = EPM. If a horse is exposed to the protozoa, it can mount an antibody titer to the organism and, in some cases fight it off. The presence of a positive titer, especially if there are no clinical signs, is not proof of actual infection. That can only be definitively diagnosed by taking a sample of cerebrospinal fluid via a spinal tap (rather drastic measure which isusually reserved for cases where there are clinical signs and a diagnosis is needed to treat it.) The organism is carried by opossums and excreted in their urine/feces. If the hay dealer has opossums either in hay storage barns or fields, it could be an issue when selling the hay. Fecal/urine contamination is the main source of infection.



This answer was written by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers University, Equine Science Center.



How can I prevent an EPM breakout on my farm?

There has been an EPM outbreak on the farm where I board my horses. What can we do to prevent further disease?




EPM (equine protozoal myeloencephalitis) is spread by the feces of opossums infected with the parasite Sarcocystis neurona. Symptoms in the horse are generally neurological. It is not contagious from horse to horse. The best way to prevent equine infection is to minimize contact with opossum waste and discourage opossums from residing near your barn. Below are some tips.


  • Horse and pet feed should be in sealed containers, preferably behind closed doors. Opossums will eat pet food left out for barn cats and bird seed.
  • Garbage should be kept in closed containers and fallen fruit from nearby trees should be removed.
  • Use a steam-cleaning method to kill infectious particles in feed and water buckets.
  • Remove roadkill from nearby roads, as it can attract opossums.
  • Do not feed horses on the ground, even in rubber tubs since opossums can still contaminate them.
  • Clean up all spilled or uneaten grain as this can be a feed source for opossums.
  • If a stream or pond is used as a water source on the farm, this water can also be contaminated with opossum waste.
  • Hay can also be a source of contamination; make sure opossums cannot access hay storage. Ask your hay provider if his/her storage is accessible to opossums.
  • To keep opossums out of fields, you can install a low electric wire or mesh fencing.
  • Opossums hide in dense shrubs and woodpiles, so clearing this kind of vegetation from your farm can discourage opossum activity. 

Resources and further reading:




My horse lost an eye. How do I get started with her again?

Due to a boarding accident, my young horse lost an eye. I was wondering what the next steps in helping her cope and riding her again would be. She is 4 years old and has been broke. Is there any literature or courses available to help me help her get adjusted in her new surroundings and with her new life?


I don't happen to know of any literature on horses with one eye, but I can tell you that trusting you will be the biggest help for her! The more she hears your comforting voice the better she will feel, even when she can't see you. Get in the habit of talking to her constantly. You might even be doing this already.


I can also say that I know a few horses with one eye that seem to be doing just fine. I have seen a horse with only one eye compete in a steeplechase over timber, I believe. It seemed that having one eye wasn't a handicap at all. I also a have a friend that has a stallion with one eye. He is still used for teasing, breeding and a little riding, and he does much better when the main handler works him and talks to him a lot. It is hard to say whether your horse will still be able to become the athlete she could have been. I recommend that you first get a strong bond between you and then continue with her training. She will tell you what she is capable of and comfortable with.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



Can I use something other than pharmaceuticals to prevent gastric ulcers?

My 20 year old horse has colicked 6 times over the last year. He has responded well to pharmaceutical treatment the last three times. We assume that his colic is due to ulcers and have since added oil, beet pulp, and lots of alfalfa to his diet and put him on a daily 1/4 tube of a pharmaceutical treatment. He seems to have bloomed both with muscle and coat since we've made the changes (and no more colic - fingers crossed). While I'm relieved and pleased with the results, the cost is killing me. Are there any other ways of dealing with his ulcer issues?


The cost of pharmaceutically treating and preventing ulcers is considerable! However, with some horses there is no alternative treatment. You might consider trying papaya supplementation, although there is no research supporting its efficacy against ulcers in horses. Some people feed papaya pills (the human variety) to their horses, others try the pulp, and some give a whole fruit a day.

Stress is a very common cause of ulcers. One management practice you can employ to reduce stress is to keep ulcer-prone horses outside as much as possible. This is the best way to decrease their stress. Some horses can develop ulcers as soon as 24 hours after being stalled if they are used to being kept outside.

Another cause of ulcers is excess gastric acid in the stomach. Unlike humans, horses produce gastric acid 24 hours a day, not just when eating. Feeding hay free choice will help buffer gastric acid. Alfalfa hay has been shown to have good buffering ability due to its high calcium content; however, you do not want to feed free choice alfalfa. Continue feeding “lots of alfalfa,” but make sure the rest of the hay in the diet is good quality grass hay. Try these management changes once the horse is clear of ulcers, as he might not want to consume free choice hay if he currently has ulcers.

Decreasing any other stressors affecting your horse would also help. Once you have taken steps to reduce his stress, try implementing some of these changes and see if they help with decreasing the severity or incidence of ulcers. These changes should be made after consulting with your veterinarian and discussing the risk factors in discontinuing the pharmaceutical treatment.


Answer provided by Carey Williams, Ph.D., Equine Extension Specialist, Rutgers Cooperative Extension and reviewed by Shari C. Silverman V.M.D., Senior Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.




My horse has a poor hair coat, is this a nutritional issue?

Last year I bought an off-the-track Thoroughbred. He had a super short, sleek, silky coat. This year he is on a low carb diet due to his past history of liver congestion. Now his coat has changed. It looks slightly fuzzy, and the ends curl upward just a little. Is this a nutritional issue or something else?



I suspect that it is diet-related. When he was at the track they probably had him on a high fat, high energy diet. The low carb diet he is on now might not have the same fat content he was used to at the track. If you can get his dietary history from his past trainer that will help you get a sense of what he used to eat. However, since he is not racing anymore he no longer needs that level of fat.

I would recommend adding at least a small amount of a fat supplement to his diet. Without knowing his dietary history I can't make any exact recommendations -- but you can try a coat conditioner or just rice bran or corn oil. He would not need much, just 1/4 cup oil or 1 cup of rice bran. This should help his coat condition.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



What causes headshaking?

I read recently that a horse that tosses its head around frequently may have a medical condition. My 2 1/2 year old Halflinger filly has been tossing her head almost constantly in the past week. She's always tossed her head around when she's excited or "frisky". I don't see any other changes in her. Three weeks ago, I moved her from a barn where she was pastured with three other horses to my own property where she lives alone. Could the head tossing be from boredom?


Head tossing or shaking in horses can be caused by multiple things. It could be a behavioral vice (possibly caused by boredom); done out of nervousness due to lack of companionship, in response to pain or irritation to flies; or caused by an allergy. Typically, if it is caused by an allergy, you will see it occur more often starting in spring and continuing through fall but almost non-existent in winter months (especially in a freezing climate). Some affected horses have more severe head shaking at rest and others during exercise. In the latter, the problem is generally exacerbated during exercise and thus renders some horses practically useless for riding, depending on the rider's tolerance level. However, take note if this behavior occurs only when riding or being handled; this may be more of a behavioral protest. If the horse shakes her head in the field even when fly population has decreased (in fall or very early spring), it may indicate an allergy-related cause. There really isn't any consistent pattern in how the problem begins; in some, head shaking arises spontaneously with no apparent change of season, ownership, barn, country or discipline.


In horses with a seasonal affliction there may also be symptoms suggestive of an allergy: nose rubbing, a watery ocular and nasal discharge, low head carriage, sneezing, snorting, head pressing, and pressing the muzzle into the ground. Head shaking has also been reported to worsen in bright sunlight, on warm and humid days or when the wind blows into the horse's face. Some affected horses will actively seek out shade. In some instances, allergens such as pollen, oilseed rape volatiles, dust, etc. can get into the horse's nose. The horse may appear to be having a reaction to an unusually irritating stimulus in the nasal passages. Horses affected with mild clinical signs of head shaking may simply exhibit mild, periodic head movements and low-grade twitching of muscles in the face, but may be rideable. Moderately affected horses may be rideable with some difficulty under special circumstances (cooler weather, protection from bright sunlight, and on non-windy days). More severely affected horses are difficult to control, uncontrollable or unrideable.


To eliminate allergy as a possibility in your horse it would be best to contact your veterinarian. There is also the possibility that a prescription allergy medicine will cure the head tossing or at least decrease its severity.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



What is the best way to manage heaves without steroids?

I have a 19-year-old gelding. He is kept in good shape with frequent dressage training and trail riding. During past summers we would only ever experience one episode of heaves, triggered by humidity. Treatment would prevent reoccurrence until the next summer. This summer he had quite a few episodes of coughing and a lot of vet calls. The vet put him on daily doses of steroids. Every time we tried to wean him off, we ended up right back where we started. What is the best way to manage heaves without steroids?



Respiratory issues can be caused by a variety of things, including internal parasites, bacterial infections, viruses, and allergies. One of the common causes of breathing issues in horses is called chronic obstructive pulmonary disease (COPD), more commonly referred to as “heaves.” There are a variety of ways to treat COPD, ranging from internal medications to changes in the environment to an entire change of diet.

COPD occurs when a horse has an allergic reaction to particles found in hay, or other types of dust. The most common allergens are certain types of bacteria, fungi, feces, animal dander and pollen. A horse with COPD will have an overactive defense mechanism to these inhaled foreign particles, which causes more inflammation in their airways than in those of a normal horse. The increased inflammation in the airways decreases the horse’s ability to get adequate air intake and causes the wheezing sounds that are associated with COPD. Some of the external symptoms associated with heaves are nasal discharge, ongoing cough and difficulty with breathing which results in abdominal breathing.

There are a variety of treatments that can help suppress the symptoms of COPD. Some of the most widely used are corticosteroids (such as dexamethasone) that help reduce the inflammation that occurs in the airways. These medicines can be given orally, intravenously, or inhaled. Although this treatment works well, there are side effects that can be detrimental to the horse if it is kept on steroids for long periods of time. A bronchodilator can also be used to treat the symptoms; these are drugs used to relax the smooth muscles in the airway and decrease the obstruction. These are safer than steroids, but generally only work better for less severe cases of COPD. These drugs can be administered orally, intravenously, or inhaled as well.

If one does not want to treat a horse with any type of drug a change in environment and diet may be attempted. One of the most important things to change is the horse’s exposure to hay. You can start by soaking the horse’s hay at each feeding for about 30 minutes. This will decrease the amount of dust. However, this might not be enough for some COPD horses. Hay cubes can also be soaked and may provide less dust than long stem hay. An all-pelleted diet of a complete feed may be the best option for a horse with severe cases of COPD. This would eliminate the need for a long stem hay or cube; however, make sure you are feeding the correct amount daily. It is best to feed these horses in multiple smaller meals daily. Feeding should also be done at shoulder level to decrease the amount of dust from the ground that can get into the food or be inhaled into the airways. However, it is also important not to place the feed too high, so that hay or feed particles do not fall into the nasal passages and get inhaled.

It is also best to minimize the amount of time that the horse spends in a stall since this is where there are high concentrations of allergens and low ventilation. If possible, leave the horse at pasture full time. This is the healthiest option for a horse with COPD. If possible, make sure that bedding is not excessively dusty. The best types of bedding are paper and peat moss. Shavings can be wet down to prevent dust. Typically, straw and sawdust are the dustiest products and should be avoided. Is it important to only clean out the stalls when the horse is not in the barn since cleaning will cause the dust particles to circulate in the air.

These practices can all be done to help decrease the symptoms of COPD before resorting to drugs; however, in some severe cases, COPD must be managed with the use of pharmaceuticals. The decision as to whether of not your horse’s condition can be managed without the use of steroids or other pharmaceuticals should be made in consultation with your veterinarian.


Answer provided with the help of Lisa Restine, Rutgers University, Animal Science Research Student and reviewed by Shari C. Silverman V.M.D., Senior Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.



Would it be beneficial to know what species of bacteria cause a hoof abscess?

I am conducting research for a thesis on the actual species of bacteria or fungi that cause hoof abscesses in horses. My Belgian stallion had abscesses in three hooves this past summer, and as a six year old, never had them in past years. My question is, would actually knowing the organism that causes abscesses change the way they are treated or is the organism irrelevant?



In response to your question regarding the micro-organisms involved in hoof abscesses, you make some good points of interest. There is no doubt that more research needs to be done in the field of podiatry and hoof-related diseases. The majority of microbiological studies involving the hoof typically implicate a mixed-bag of different organisms including bacteria and fungi. Few have been implicated in the pathogenesis of abscesses, however, no one organism has been identified as the sole culprit. The hoof is a tissue that is normally heavily populated with bacteria on the surface. It is probably more important to identify which and how many organisms naturally inhabit the tissues at deeper levels.

Be encouraged to continue on your academic path and if contemplating such a research study, engage the services of a microbiologist who is familiar with such microorganisms, knows appropriate ways of culturing them, and can address the complexities with accurate growth and identification of them. Many of the relevant reports lack sufficient scientific inquiry, which renders the results unreliable.

With regard to your comment of bacterial identification and an appropriate treatment regime, most veterinarians accept that bacteria in general play a primary role. With the proximity of fecal material, gram negative organisms such as E. coli are involved, however, there are gram positive bacteria that can also be implicated. Antimicrobial therapies, such as antibiotics, are based on the speculation of specific bacterial involvement. You are correct that accurate identification of the bacteria would determine which medication would be most appropriate. Antibiotic treatment of hoof abscesses is rare in veterinary practice. Clinical experience has shown that antibiotics do not help the situation and can actually slow down the healing process. Many question whether antibiotics circulating in the blood stream can actually penetrate the tissues where the abscess is located. In treating abscesses the goals should be to determine why they are occurring (especially with repeated episodes), establish drainage, and utilize osmotic agents such as poultice and Epsom salt to draw out the moisture from these pockets of pus.

The answer to your question as to if knowing which bacteria was involved in an abscess, would the treatment protocol change? Probably not. However your speculative research could provide some valuable insight into the disease process and quite possibly help the practicing veterinarian.

This answer was written with the help of Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University and approved by Nancy E Halpern, DVM, Director, Division of Animal Health, New Jersey State Veterinarian, New Jersey Department of Agriculture.


Are hydroponic (germinated) barley and other grains good for horses?

I have been reading up on using hydroponic fodder systems to grow feed for horses. Most of the information has been on sprouted barley and I am wondering what the nutrient composition of this feed might be and if it would be good for horses? Are there other types of grains which could be grown this way that would be better suited for horses? Are you aware of any research that has been conducted in this area?



Sprouted barley grains can be fed as loose feed or just feeding the greens as forage. The picture to the right shows sprouted barley that is fed to horses in Europe. Research on feeding sprouted grains to horses is sparse. For additional information, click on the following titles:

Hydroponic barley sample.

Review of Hydroponic Fodder Production for Beef Cattle

  • The review summarizes much of the research up to 2003
  • Many trials show no advantage to feeding sprouted barley over grain barley
  • The cost of growing sprouted barley hydroponically created an economic disadvantage
Feeding Value of Hydroponically Sprouted Barley for Poultry and Pigs
  • Research trials that have been conducted with pigs and poultry
  • There was no research available on using this technology in horses
Feeding Value of Sprouted Grains
  • Reviews various sources of research (excluding horses) on feeding sprouted barley to livestock

A concern is that moist materials run a greater risk of becoming moldy. This is a common problem in hydroponic fodder systems. Ruminants such as cows are not as affected by mold as horses, which can easily become very ill or even die from eating small amounts of mold.


Even in the cattle feeding trial, sprouts were used as a supplement to pasture. It has also been found that the grains lose nutrients during the sprouting process.


Here is a research article about this. The younger the sprout, the higher the nutrient value (i.e. energy, protein, and digestibility); therefore, feeding them earlier is preferable.


Germinated barley is being fed to horses in Europe (see EDHYA Form) and can be made at home by horse owners. If you do try producing this, then the utmost care must be taken to avoid mold and toxins. There is still no research that has been conducted on this feed product for horses; this answer is just summarizing the research currently available. The Equine Science Center is unable to provide feeding recommendations without scientific evidence that it is safe and effective.


From a nutritional perspective, hydroponic fodder is concerning when you consider the amount you would need to feed and the imbalance of minerals that it provides.

If you go to Global Fodder Solutions it gives the certified nutrient analysis. The fodder is only about 13% dry matter, which means you are paying quite a lot for something that only has 13% of usable nutrients; the rest is water. To meet the usual dry matter intake of the average horse (~25 lbs per day) you would have to feed a large amount of the fodder to meet these needs if using it as the only feed source, as sometimes suggested. Plus the calcium to phosphorus ratio is reversed (0.57:1) where horses require a 2:1 ratio. It is also very low in fiber. This would make it inappropriate for growing horses and even adults on a long term basis unless balanced with another source of calcium and fiber. It could possibly be considered for a horse that does not drink well and has a chronic problem with impactions, but the horse would need a calcium supplement to help balance out the diet.



My horse is acting like she has HYPP; is there anything else it could be?

Do you know if there is a plant or weed in the northern Texas area that can create symptoms similar to HYPP in horses? My horse has an unknown history, but is a stock type breed and has recently moved to Texas. It has severe muscle contraction, sweating and grinding of its teeth. It will also stagger on occasion. The mare has elevated but normal potassium levels and was treated with a diuretic and sugars. It has now been taken off all pasture and is on a strict grass, hay, and oat diet. Previously it was on pasture 11 hours per day with alfalfa and sweet feed. The mare has continued to improve over the last week. However, after the last severe attack, it has cuts on its hocks and above its eyes suggesting mild attacks. The horse had mild muscle spasms by its girth area and has exhibited colicky behavior (rolling, etc). Now the mare is really stressed because it cannot go out with buddies in the pasture but has shown no reoccurrence of the severe episode. Could you please provide me any information or direction?



I am a little unclear about a couple of your comments. You mentioned she had elevated potassium levels but also said they were normal. It was also wise to stop feeding alfalfa. Alfalfa and sweet feed plus good quality pasture yields a high potassium feeding regimen. If the mare is indeed HYPP, that combination would definitely trigger attacks. If none of the other horses on the pastures seem to be having similar problems, I would have her tested for HYPP.


Stressful situations can certainly bring on attacks. Moving to a new location and having new pasture/stall mates could definitely be a factor. Get the mare stabilized before considering the next activity.


If other horses on the pasture are having similar problems, I would recommend that you reach out to an agricultural/extension specialist through Texas A&M University to assist with your plant-related questions. Another recommendation is that you speak with one of the doctors at the College of Veterinary Medicine at Texas A&M regarding diagnostics, treatments, and preventative measures that your mare might need. It almost sounds as if she needs to be maintained on acetazolamide until she gets back to a more normal potassium level. It does seem to me that your mare needs to be examined at by a veterinarian who is comfortable with treating HYPP. I believe that most veterinarians will want to evaluate the mare in person rather than treating over the phone or via email. You may have to consider shipping the horse to a referral hospital or veterinary school. If this is not possible, perhaps A&M can recommend veterinarians in your area who may be more comfortable with treating your horse.


This answer was written with the help of Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University and Sarah Ralston, VMD, PhD, DACV, Associate Professor at Rutgers University..




What is HYPP? Should bananas be fed to horses?

An exceptionally beautiful Quarter Horse eats a banana, goes into uncontrollable muscle spasms and paralysis, suffers irregular heartbeat and obstructed airways, then topples over and dies. What was wrong with the banana?



What was wrong with the horse? It had a defective gene--the same one responsible for its beautiful musculature--giving it "Hyperkalemic Periodic Paralysis". Evidence suggests these horses inherited the gene from one particular Quarter Horse stallion, Impressive, used as a stud in the 1970s and 1980s. Impressive was famed for his outstanding musculature, and since this trait was passed to his offspring, he became a popular stud. Unfortunately it is now known that the disease HYPP has passed through his genetics as well, affecting 50,000 horses, or .25% to .4% of quarter horse bloodlines. The defect is found in the DNA coding for the protein that regulates the concentrations of sodium and potassium on either side of cell membranes. Also called a sodium-potassium pump, this mechanism keeps sodium in high concentrations outside the cell, and high potassium concentrations inside the cell. When the pump opens to allow the passage of these two elements, the rush to balance the concentrations on either side of the cell causes an electric charge, which in turn allows for muscle contraction. Unfortunately in horses with HYPP, the sodium leaks into the cell at a faster rate, which alters the time it takes to build up voltage for a muscle contraction. During an attack, the blood is saturated with potassium in an effort to maintain the equilibrium.


The effects of this defect are apparent in the most common symptom of the disease: muscle trembling. Other signs are: prolapse of the third eyelid, stiff jaw, increased respiratory rate, generalized weakness or specifically weakness in the hind end (dog-sitting), complete collapse, and an abnormal whinny. These symptoms are visible only during an attack. The high potassium concentration is exclusive to an attack as well, and under normal conditions an afflicted horse would show regular blood potassium levels. Tests can be done to identify the gene, so it could be eliminated in a single generation. Horse owners, however, may not want to get rid of the gene, which adds to the muscling of the Quarter Horses, raised as much for show as for racing. Alternatively, the disease can be controlled via diet and diuretics (see "How effective is acetazolamide in the treatment of HYPP?")


Question and answer provided by Bill Sones, co-author of “Strange but True”. Answer edited by Carey Williams, Ph.D., Rutgers Cooperative Extension.




How effective is acetazolamide in the treatment of HYPP?

How effective is acetazolamide in the treatment of HYPP? I have a 9 year old Quarter Horse who has had increasing numbers of HYPP attacks over the past several months, and my veterinarian recommends that we put him on acetazolamide to help regulate the HYPP and his potassium levels. Would he have to be on it for the rest of his life, or just during the attacks?



Acetazolamide is “a potent carbonic anhydrase inhibitor” also known as a diuretic. Common uses of this drug are to control fluid secretion, treat convulsive disorders, and increase fluid secretion from the kidneys. It is recommended for the treatment of HYPP during an attack because it quickly and efficiently lowers the potassium concentration in the blood through urination. Some handlers also find it useful to keep acetazolamide in the horse’s diet constantly. It has a history of reducing the frequency and severity of the attacks. It does not have any negative affects on the horse, and is fairly inexpensive. However, it is not necessary to keep acetazolamide in the diet unless the horse is prone to severe attacks. Acetazolamide is forbidden under AQHA and AHSA regulations, so the alternate drug hydrochlorthiazide is sometimes substituted.


HYPP attacks fall into two categories: mild and severe. Mild attacks occur when there are muscle tremors, but the horse can stay on its feet. In this instance the best treatment is to walk the horse to stimulate adrenalin production. Again, acetazolamide can be administered to help the animal lower its blood potassium levels through urination. An alternative treatment is feeding grain in an attempt to boost production of insulin through carbohydrate metabolism. In the case of a severe attack (when the animal is down), veterinarian assistance is required to help the horse regulate its blood potassium concentration. This is done by administering dextrose (a sugar) or calcium intravenously. Sometimes a shot of insulin will boost the intake of potassium into the cells. Veterinarians have used epinephrine to help during an attack because, like insulin, it promotes the absorption of potassium out of the bloodstream and into the cells. As with mild attacks, it is also common for veterinarians to give acetazolamide to the animal in an additional effort to expel potassium.


Like many genetic diseases, the severity of the affliction varies with the individual. Some horses may test positive for HYPP and never show signs of an attack. Others my have severe attacks more frequently. If a horse doesn’t show signs of HYPP, there is no need to change how you manage that horse. For a horse with symptoms, a simple control of diet and exercise can help reduce attacks. Attacks are triggered by stress, dehydration, extreme temperature, intense exercise, anesthesia, foods high in potassium, sudden dietary changes, and transport. Therefore, an established feeding schedule with feeds that are low in potassium (grains, oat hay) and little or no high potassium feeds (molasses, alfalfa, timothy hay) is effective. The horse should be fed about three small grain meals per day, and like all horses have constant access to a salt block and water. Acetazolamide could also be administered twice a day. Daily and nightly turnout is preferable in order to give the horse constant access to pasture. A constant exercise schedule is also favorable. Also, informing the veterinarian of the horse’s condition will help if the animal is ever put under anesthesia, which often triggers attacks. Most HYPP attacks are never treated, and the animals are able to recuperate on their own. However, with these few guidelines in management, a horse owner could minimize his animal’s discomfort and continue to enjoy all the pleasures that horsemanship provides.


This answer was prepared with the help of Cara Allen, Animal Science Research Student at the School of Environmental and Biological Sciences at Rutgers University, with references from Sharon J. Spier, University of California.



What is a good low protein diet for a horse with kidney disease?

My 25 year old Saddlebred has been diagnosed with kidney disease. I was able to get him to eat rolled oats and a little bit of sweet feed and first cutting grass hay. He’s eating the hay well. However, I am not sure if this is the best low protein, phosphorus and calcium diet?



You actually have the horse on a very good low protein ration right now. On the east coast, grass hay is usually less than 10% protein and less than 0.6% calcium if grown locally. Oats are about 12% protein; if lower protein is desired, you could use cracked corn (8 to 9% protein) instead. However, be aware that one “scoop” of corn will weigh almost twice as much as oats and provide more than twice the energy. Corn is actually a preferred feed choice for kidney failure, because it is a great source of calories with very little volume and extremely low calcium. Protein is only of major concern in advanced stages of kidney failure as a rule. The horse should definitely have access to a salt block and free access to water.
If your horse is maintaining weight on the current regimen, don’t change it. If it is underweight or losing condition, try switching (gradually) to the corn. If the horse’s hair coat starts to look dull and coarse, more protein may be needed. In that case, switch back to the oats or add in 4 to 8 ounces of soybean meal daily.



Do horses get Lyme disease?

Do horses get Lyme disease? I am constantly pulling both deer and dog ticks off of my pastured horses. Frequently, there is a swelling at the site where the tick was. However, my horses have no health problems. Should I be concerned?



Like humans and general house pets, horses can get Lyme disease from deer ticks. The bacterium which causes Lyme disease, Borrela bungdorferi, gets transferred to the animal through a bite usually in the spring and early fall periods. One of the most obvious symptoms of Lyme disease is a bulls-eye rash that surrounds the bite area, which can appear between 3 and 30 days after the tick bite. Some other symptoms have included fever, depression or other behavioral changes such as increased irritability, swollen legs, lameness, skin lesions, and stiffness. However, later stage Lyme disease can include more serious symptoms such as arthritis and neurological as well as cardiac abnormalities. Sometimes the horses might not even develop signs of Lyme disease but still have it.


Diagnosing Lyme disease in horses is difficult because a lot of the symptoms associated with Lyme disease can also occur from other problems, or from lameness. Even if blood test results come up positive for Lyme, it may only mean that the horse has been exposed to the bacterium over the years but its symptoms are not due to Lyme at the present time.


Antibiotics such as tetracycline can be given successfully via an intravenous line. This treatment can help alleviate symptoms after the first day. However, oral and intramuscular medications can also be used. All of these treatments may need to last for a few weeks, depending on how well the animal is responding to the medication. During the first few days of treatment, monitor your horse to make sure its symptoms do not turn into true laminitis.


There are some steps you can take to help prevent Lyme disease. Use a tick repellent on your horse, and keep pasture grasses low. Regularly groom your horse during peak tick seasons, and immediately remove any ticks you find. Ticks need to attach and feed for 12-24 hours before they can transmit the bacteria.

There is no USDA approved Lyme vaccine for horses, however, there is testing on  a vaccine in progress.  Some people are using the canine vaccine in horses, however, it is not recommended without consulting with an equine veterinarian.  Some of the canine vaccine side effects could also be problematic in horses.

This answer was prepared with the help of Erin Rockhill, Animal Science Research Student at the School of Environmental and Biological Sciences, Rutgers University.



Can I treat Lyme disease at home instead of a veterinary clinic?

I have a horse that is 22 years old and has Lyme disease for a second time. I am afraid to transport to a clinic for IV treatment. Can the horse be treated in the barn with oral medications or injections?



This is something which should be discussed with your veterinarian. There is a lot of debate regarding Lyme disease and blood titers. Some veterinary practices prefer to treat with intravenous tetracycline for a period of time where others prefer to treat with oral doxycycline. Whether this can be treated in the field versus in a clinic situation is dependent upon the veterinarian as well as your financial situation. Intravenous tetracycline must be administered slowly over an extended period of time (10-20 min) on a daily basis. This can become expensive when done in a field situation. In addition, the logistics of this treatment course must also be considered. Your veterinarian would be better to answer this question.


This answer was written with the help of Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University and approved by Nancy E Halpern, DVM, Director, Division of Animal Health, New Jersey State Veterinarian, New Jersey Department of Agriculture.



I think my horse has a neurological problem. Can you help?

I just purchased a 5-year-old Hanoverian mare. She has a very strange way of standing. Most of the time, she has her left forefoot directly in front of her right fore. When she is nervous, or you attempt to pick up a rear hoof, she taps on her right front toe with her left front hoof, actually scuffing her right front hoof. She is also able to totally cross her left leg over the right leg, placing it on the ground on the outside of her right leg. She will stay like this for more than a minute, and appears totally comfortable. Also, she refuses to give her rear hoof for cleaning and is uncomfortable when I ask. If I succeed she trembles in front and sways. I worry that she might collapse or go down suddenly if I were to ride her.


It sounds as if your mare may have a back or hip problem or perhaps a neurological deficit affecting her proprioception (ability to maintain her balance and "know" where her feet are). The signs you describe are not "classic" for wobbler’s syndrome, but she could well have a spinal lesion affecting her balance. If she drags her hind feet when asked to back up I would be more suspicious of wobbler’s syndrome. It is a good idea to ask her previous owner about any history of head/neck trauma – did she exhibit this behavior before the purchase? I strongly suggest that you have an equine veterinarian with experience in neurological problems give her a thorough physical. From what you describe, I would recommend not riding her until you find out what the problem is.


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.



Is potassium iodide safe to use on scratches?

It was nice to have found your site and I am looking forward to receiving your perspective on whether the use of potassium iodide in combination with olive leaf extract would have a beneficial effect on pastern dermatitis. I am led to believe that Potassium Iodide can penetrate the membrane around the follicle and olive leaf extract can rid the body of many toxins and infections, etc. I do recognize that horses and humans have good tolerance to these herbs but, I am finding it very difficult to find accurate dosage information. Possibly you could provide that?


Potassium iodide is a very strong salt and will cause severe irritation and pain, especially if applied to an open wound. Your horses would probably object to its application immediately. I have seen no studies of the safety or efficacy of olive leaf extract, in humans or horses. If you are having problems with pastern dermatitis, the only way to control it is to keep the horses' lower legs as clean and dry as possible. Picking-up manure from heavily trampled areas of paddocks and stalls on a daily basis will dramatically reduce your problems (as well as eliminating thrush!). Regularly cleaning the pastern area (once a week or so) with a tamed iodide soapy solution, like betadine scrub or povidone iodine, can help but avoid irritating the sensitive tissues if possible. Daily applications might dry out the areas! However in veterinary cases such as this, it is very important to get an individual
consultation from an equine veterinarian.


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.




How do I get rid of rain rot?

I have an Appaloosa that has encountered problems with rain rot on his back/rump area this past spring and again this fall. We've treated it with iodine shampoo and ointment. It seems to work, but it takes four to five weeks for healing to occur. During that time he is very sensitive, to the point where he can't be ridden. Is there a better, quicker treatment? Better yet, what are some preventive steps to prevent this from happening?


Rain scald (aka “rain rot”) is a condition similar to mud fever, except it affects the back, flanks and hindquarters. It is a bacterial (Dermatophilus congolensis) infection of the hair follicle resulting in scabby lesions, hair loss, and inflamed, irritated skin. In extreme cases it can result in severe pain and loss of body condition. In its early stages, small bumps are felt when a hand is run over the infected area. These bumps enlarge into scabby and painful lesions.


Rain rot occurs most commonly in horses turned outside full-time, usually during humid and persistently wet seasons. Repeated exposure to moisture softens the skin and washes away the natural oils that protect the hair follicle, allowing bacteria access to the site of infection.


It is important to treat rain scald as soon as it is detected, as this will speed up the healing process and help prevent more severe or secondary bacterial infections that can become persistent and difficult to treat. In mild cases, simply keeping the skin dry, removing the scabs and gentle grooming should take care of the infection. Dermatophilus congolensis is an anaerobic organism (one which thrives in the absence of oxygen), so removing the scabs is important. Be thorough but gentle when removing scabs, as this process may be uncomfortable to the horse.


With more severe or persistent infections, scabs should be removed and a medicated shampoo used to thoroughly cleanse the infected area. The clean open sores should be kept dry; only large gaping sores should be treated with an antibiotic ointment to help prevent secondary infections. There are several over-the-counter medicated or iodine shampoos that work for mild to moderate infections; however, a prescription medicated shampoo and possibly a systemic antibiotic should be obtained from a veterinarian for severe or persistent infections. The afflicted areas should be washed daily until the infection is resolved. Consult an equine nutritionist or your veterinarian if your horse shows signs of losing body condition. They can help you safely and effectively adjust your horse’s diet to counter this.


There are situations where bathing the horse is not an option (such as in extremely cold weather). Anecdotal reports indicate that daily spot treatment (following the removal of scabs) with anti-microbial agents such as chlorhexadine or povidone-iodine helps remedy the infection. This process tends to be tedious and messy, however, and generally results in a longer healing time.


In any case, be sure to thoroughly wash your hands with soap and water, disinfect your grooming tools, and wash halters, saddle pads and blankets after every exposure to infected skin to prevent re-infection or transferring the bacteria to other animals. A 5 - 10 % bleach solution will do the trick. If keeping horses out of the elements is not an option, use of a fitted rain sheet or blanket can help keep the skin dry in inclement weather. Be sure that your blanket is truly waterproof before use, otherwise it may work against you by trapping moisture against your horse’s skin instead of keeping it off. As always, proper nutrition, regular grooming, and keeping pastures and facilities clean can help prevent rain scald.


Specifically for your case, I would recommend consulting with your veterinarian. He or she will probably suggest discontinuing the ointment as it may be working against you by providing a moist, anaerobic environment that the organism thrives in. Additionally, it may not have strong enough antibiotic properties to completely kill the organism. I would recommend gently picking those scabs and getting some prescription medicated shampoo from your veterinarian and using that daily for at least a week or until the infection is resolved. In my experience it works very well and in most cases clears an infection up faster than other spot treatments. If the infection is severe or persistent enough, you might want to discuss using an oral antibiotic with your vet. As for prevention, make sure you clean and disinfect anything that comes into contact with the infected skin to prevent re-infection. Keeping your horse clean and dry will allow the natural oily skin secretions to protect against infection. This is probably the best defense against rain rot.


This answer was prepared with the help of Emily Lamprecht, Rutgers University, Doctoral Graduate Student in Animal Science and reviewed by Shari C. Silverman V.M.D., Senior Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.


Could you please tell me what ringbone or sidebone is, and what can be done about it?


What is ringbone, or sidebone, and what can be done about it?




Ringbone in horses is a calcification of the bone or cartilage in the pastern and coffin bones. High ringbone is calcification which occurs on the lower part of the large pastern or the upper part of the small pastern. Calcification which occurs on the lower part of the small pastern or the upper part of the coffin is known as “low ringbone.” Ringbone typically causes arthritis and new bone growth, which will sometimes fuse pastern bones and cause a decrease in flexion as well as lameness. Sidebone is a calcification of the lateral cartilage of the coffin bone inside the hoof. Here calcification turns to bone and subsides to a blemish that might not ever cause lameness.


You will be able to see or feel ringbone in horses just above the hoof in the area of the coronet band or pastern. It will feel like a hard lump or a ring of excess bone. If the problem is not causing lameness, nothing needs to be done; it is just a blemish and will not detract from the use of the animal. However, in cases where lameness occurs due to ringbone, and assuming that the horse’s feet are consistently and adequately trimmed, using a shoe that provides an easy breakover or making the toes shorter may help with the animal’s comfort.


In the short term after diagnosis, rest and anti-inflammatory drugs (e.g. Bute) will probably be prescribed. Cold hosing the area for 15 to 20 minutes twice a day is also a good way to alleviate swelling and maximize comfort. Depending on the severity, or if it has already progressed into arthritis, your vet might recommend corticosteroid injections or a regimen of joint injections to prevent chronic inflammation.


The best chances for a sound recovery are early detection and proper treatment, so it is advisable to work with an equine veterinarian to properly treat the ringbone and/or sidebone and find the option that is best suited for your horse.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



What is the best treatment for ringbone?


I am working with a horse that was diagnosed nearly two months ago with ringbone. The veterinarian told the barn manager that it will take 6-12 months for the joint to fuse and to give it phenlybutazone for the pain. I did a little research and found a supplement I could also give her. She was on the supplement for a month and was improving and walking a little better but the veterinarian said to take the horse off the supplement because it was interfering with the joint fusing. I can’t seem to find any information on what to do for a horse while the joint is fusing. The farrier has also said not to put shoes on her until the joint fuses. This is the first case of ringbone at the barn and we would like to do what is best for the horse.




Ringbone is simply arthritis of a joint. High ringbone is arthritis of the pastern joint and low ringbone is arthritis of the coffin joint. There are a multitude of different philosophies and treatment options out there. So there is no right or wrong answer here in this situation. Much of the treatment should be based upon the occupation of the horse, ability of the horse, and expectation of the owner/trainer. Typically once the joint fuses, the horse should go sound. Until then it is a little bit of a “roller coaster” regarding lameness. In some cases, the joint never does fuse. There are medical and surgical options out there to help promote the fusion of the joint in hopes of speeding up the process. Again every horse is different and the process may be faster or slower than expected in each case. It is best to try to keep the horse in work and treat with pain relieving medications such as Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and intra-articular injections of cortisone. Unfortunately, these are only temporary. But the hope is that while the horse keeps working, the cartilage wears down through the exercise promoting the bone to fuse. Sometimes the protocol works, other times not as well. Financial resources and the wishes of the owner often dictate how aggressive to pursue the process of fusing the joint. A surgical fusion on the east coast will cost around $5,000-6,000 and will have the horse out of work for almost a year.


Joint supplements are designed to help maintain the cartilage and slow down the arthritis process. There are decent supplements on the market that have worked in several cases. There are a multitude of different ones out there with similar results. Again, everyone has a different approach to treating this disease and each horse follows at a different speed of recovery. The key is to keep the horse comfortable while this process takes place.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.




How can I tell if my horse has ringworm?

I have a horse that may have dry seborrhea or possibly ringworm. How can I tell the difference, and what treatments should I use? The symptoms are small dime-sized circles of hairless areas where the skin has crusted off and taken all the hair with it. These areas are mainly on the neck and shoulder. They are not oily; they are completely dry. The area on the shoulder is much broader and less defined in its shape. The horse does not seem to be itchy. There seems to be dandruff on his body when brushing other areas.


From your description, it sounds like ringworm. The nice dime-sized round circles of scabs that remove the hair are the key. Depending on when the scabs are removed they may have a yellowish pussy layer under them, or they may leave the skin dry and scaly. The best treatment for this is to first clip the hair away from around the infected area (don't need to clip the whole neck, just extend the shaved area so there's a 1/2-inch margin of unaffected skin around each lesion). This will remove the fungus' main food source: keratin, the protein in the hair. Then wet the shaved area with a sponge and wash with an antifungal antiseptic solution like Betadine, Novalsan, or dilute bleach solution (1 part bleach to 10 parts water). Make the spot lather up and leave for 10 min to kill the fungus, then rinse thoroughly with water. After the rinse you can apply a vinegar solution (2 tablespoons white vinegar in 1 quart of clean water) to affected areas with a sponge or spray bottle. This solution creates a slightly acidic environment, which the fungi don't like. Dry the wet area well, especially in cold weather. After this step you can apply an antifungal dressing (Betadine ointment, or athlete's foot product) obtained at your local pharmacy or tack shop to kill any remaining fungus on the skin. Repeat this process daily for a week then every other day until the lesions are shiny with new hair growth. It is very important to keep the lesions clean, dry, and exposed to air and sun. Do not blanket him if you can help it. The lesions need the air to heal, plus the blanket could be aiding in spreading the fungus. Also, ringworm is contagious to humans, so you need to disinfect EVERYTHING that has come in contact with the lesions, including any sponges, brushes, clippers, blankets, gloves, fingers, etc.


If this treatment does not work, there may be another problem, or the fungus has infected the area more severely and you should consult with your vet. Keep an eye on the area for healing progress and/or any new lesions developing; you may need to continue treatment if they start to reappear.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



How do I treat my horse's runny nose?

I have a mare that has had a persistent runny nose; it has been on and off for several months. It started with a little trickle and turned into an infection. I have been in constant communication with the veterinarian but I think he is also a little baffled. The mare received two sulphur-based antibiotics, and the infection starts to clear and looks great and then a week later the nasal discharge is thick and white. We have just had her blood analysis performed and it showed a low red blood cell count and slight anemia. The veterinarian has advised giving the horses a blood iron supplement, and strong antibiotics IV. The last resort would be an X-ray of her head for signs of a sinus infection, but my budget is severely strapped. Maybe you could shed some light; I appreciate any advice.


I agree with your veterinarian and have some concerns that this may be a sinus related issue. The duration and one nostril involvement is rather suspicious of such a condition. There is also the guttural pouch to consider in this scenario. Any of these anatomical locations can develop low grade infections that present with prolonged nasal discharge that don’t cause any depression, lethargy, or otherwise “sickness” in the horse. When there is sinus involvement, you worry about whether there is a mild tooth-root infection which may be the primary cause of the secondary sinus infection. So unfortunately there are a host of different locations which can be the origin for the problem.


Much like your veterinarian, I would recommend further diagnostics to isolate the problem. Radiographs and endoscopy would by my recommendations. I do understand the situation that you are trying to minimize expenditures. However, consider how much money you may be spending on repeat examinations and medications that help for a short period of time.  Another option would be to go with the larger up front expense and aggressively treat it in hopes of complete resolution.


I am sorry to say, that you are not the first horse owner to experience this frustrating condition. While I know that cost plays a huge role in this scenario, you may be forced into making some additional investment into the veterinary care in order to “resolve” the condition.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



How do I treat scratches?

How would you treat scratches (the scabby, greasy condition some horses get on their fetlocks)? A Quarter Horse in our barn has had a very bad case. He was treated with various remedies with some (but not total) success.



Scratches can be tough to beat and is painful for the horse. The main thing to do is control moisture so that healing will take place. Depending on the severity of this case, it may be best to have a veterinarian examine the horse. If the horses leg(s) are warm and/or edema (swelling) is present, the horse may have developed a more severe infection or cellulitis (bacterial infection of the skin).

I have a homemade remedy that I use for a variety of “scratches”-type problems. I mix equal parts of furacin ointment with baby diaper rash cream (zinc oxide). The bacterial action of the furacin works on the infection and the zinc oxide keeps the moisture out to promote healing. I use a generic creamy diaper rash cream which mixes easily with the furacin.


Answer provided by Karyn Malinowski, Ph.D., Director, Equine Science Center and reviewed by Shari C. Silverman V.M.D., Senior Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.



How do I treat a sinus infection?

I have a three year old miniature mare which developed a hard knot on both sides of its face along the nasal cavity. The mare was placed on penicillin. Afterwards, one side opened up and began draining, although the hole is very small with little drainage. The mare doesn't seem to be in pain and this has not affected its appetite. I'm thinking it's a sinus infection. What should I do?



It is difficult to diagnose the condition without seeing the swelling and draining tracks. Sinus infections can create holes out of the skin (fistulas) to drain. Although this is rather rare in a three year old, it is not unheard of.

Given the description, ask your veterinarian to evaluate your mare. An evaluation would consist of a thorough physical examination, radiographic assessment of the masses and consideration of an endoscopy to isolate the source of the drainage. Miniature horses are notorious for having teeth-related issues which can create secondary sinusitis. In any case, it is definitely recommended to get the mare thoroughly evaluated by your veterinarian.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



What can be done for sleep deprivation or narcolepsy?

I have a 12 year old horse that won't lie down to sleep and it cannot lock its legs in order to sleep standing up. I have had the animal for almost five years and its sleep deprivation is getting so bad that it was observed falling down. The horse woke up when it hit the ground and looked a little disoriented before getting up again. This is a recent development. Usually, the horse will catch itself and wakes up before falling down. Often, it will land on the front of his ankles, and they are now permanently scarred. The horse even does this while I am tacking up to ride. I am very concerned for its safety and that of the people who work around it. Have you ever come across a case like this and do you have any ideas on what I can do to help this horse.



This is a condition that should be discussed with your veterinarian to perform any diagnostics and/or treatments. Having said that, it appears that what you are describing with your horse is not sleep deprivation, but rather the opposite: narcolepsy. I have seen this in several horses; it is not as uncommon as one may think. The hallmark clinical sign is the pronounced scars on the front legs (over the fetlocks and knees). Affected horses typically fall at a predictable time, for example on cross ties or in a stall. Typically horses do not fall during exercise.


As you mentioned, human safety is important in these situations. If one can determine the horse’s pattern and avoid it that is ideal. One should not have to remove a narcoleptic horse from work, riding, training, etc. As for the horse’s safety, wrap the front legs with standing bandages to minimize trauma if the horse falls in a stall; however there are also safety concerns for horses when keeping leg wraps on for prolonged periods of time.


There are few diagnostics for narcolepsy. The veterinary profession does not have extensive “sleep centers” like human medicine does. A few veterinary schools have conducted research on these types of conditions. These clinics can perform 24-hour heart monitoring and time lapsed cinematography to evaluate the horse’s condition further. Unfortunately, to my knowledge, there is no treatment for this condition. Therefore, managing the disease is about the only thing that can be done.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



What would cause small circles of raised hair on my horse?

We have a horse at the barn where we ride which has unusual hair formation. We are not sure of exactly what it is. The hair formation has recently developed and appears to just be raised circular spots. There is no skin abnormality underneath, the area does not appear to itch or bother the horse, and it does not appear to be ringworm. Any suggestions?




On occasions when these spots occur, they are initially thought to be ringworm; however, it typically turns out to be allergic hives that respond to a course of steroids. The image shown is of a horse with similar lesions. This horse responded to corticosteroids, although some antihistamines would have been effective as well. It is difficult to accurately diagnosis the condition over an email; therefore, one should consult a veterinarian.



* Photo by Michael Fugaro




My horse has sores in his ears; what could they be?

Our horse has red bloody sores in his ears. They are raised and about 1/2" in diameter. They appear, stay as large bumps for a while and then seem to open/bleed, dry up and do it again. Any suggestions as to what this might be?




Horses can get a multitude of sores and masses in their ears. Frequently they develop aural plaques however they are usually white and are minimally raised. They can also develop benign masses called sarcoids in their ears. Aural plaques and sarcoids can become raised, ulcerated, and relatively large in size. These are probably the two most common masses; however, there are others. Some have treatment options, while others have few. Consult your veterinarian for further information. In some circumstances, the veterinarian will take a biopsy in order to determine a treatment protocol.




My horse just passed a stone! Does he need more water?

My horse just passed a stone in his feces. I think it was because I switched him with a neighbor's horse and therefore he didn’t have a regular supply of clean water. He won't drink water unless it is clean. Can you help?



If there was only one stone and it was in his stool, I wouldn’t worry. If it was fairly round and smooth, I'll bet that if you cracked it open you'd find something like a nail or a piece of metal at its center. The horse's intestine is a bit like an oyster - if something irritating is ingested it will cover it with layers of mineral like a pearl, creating what is called an enterolith (intestinal stone). (This is especially likely if the horse is on a high mineral feed like alfalfa.) If the "environment" in the intestine is right, sometimes even minor irritants like sand can cause multiple stones which can be a real problem. These stones usually have multiple "facets" due to rubbing together and are fairly small. A single stone will be round, and, if passed, as your horse's was, solves the problem. Enteroliths can get so big that they cause intestinal blockage (colic) but it sounds as if your horse has "solved" the problem on his own!


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.



My horse has stones in her udder (lactoliths); is there a treatment or prevention for this?

I'm writing in reference to my 26 year old mare. Three weeks ago the teats of her udder suddenly appeared enlarged and were leaking fluid. The veterinarian came out and while stripping fluid, three “beans” came out on one side. The fluid stripped was not clear and had floating particles in it. The veterinarian gave my horse a time release injectable antibiotic and then returned four days later for another antibiotic injection and also injected "dry cow" into the teats. My veterinarian looked at the fluid under the microscope and said there did not appear to be any malformed cells, but she wanted to send the “bean” collected for histology. It came back as a lactolith. Since that visit, I have expressed three additional beans, and there is currently one in the udder I was unable to express over the weekend. The swelling is only marginally improved and fluid still drips at times. I am not stripping fluid unless I feel a bean and I'm only checking her once or twice a week. I am not sure what to do at this point. My veterinarian has feelers out to colleagues in internal medicine and dairy farming, but so far, no one has any idea what we need to do to return her udder to normal and stop the production or dropping of the lactoliths. There was one suggestion to radiograph the udder to see how many lactoliths are in there or how quickly she is producing them. Are there any dietary changes I could make? Or are there any other ideas you could give to help me with this problem?



Lactoliths are very uncommon in horses. It is prudent that your veterinarian has thoroughly evaluated the horse and is consulting others. A brief literature search on equine lactoliths revealed rather basic information stating that the stones can be found in large animals. The majority of the references were in surgically related categories. There was nothing that discussed the etiology and preventative measures that you are seeking.


It is recommended to identify the chemical composition of the lactoliths. Then consider additional diagnostics such as radiography and ultrasound. You could also consider surgical options such as theloscopy, where a camera is passed up the teat to view the stones. That being said, determining how to prevent these from occurring may be extremely difficult. It is unclear whether diet will have much of an influence on the prevention of these stones. However, there has not been any research on this area. On the more radical side, you could consider a mastectomy (removing the udder) as a permanent treatment option. This surgery can be rather aggressive as well as challenging. This is an interesting case that would benefit from referral to a veterinary school or referral surgical facility. A veterinary school might have the resources and diversity of proactive minds to formulate a plan for your mare.




How can I prevent the transmission of strangles?

I am organizing a small show at a local stable. A few nearby barns have had cases of strangles. Is there any way to find out where strangles outbreaks have occurred (in order to have entries from those farms bring a health notice)? Also, what are some suggested best practices to avoid or minimize the chances of strangles transmission?



Strangles is a highly contagious disease caused by the bacterium Streptococcus equi. Found throughout the world, strangles is considered to be an obligate parasite of equine and now known to survive mostly in moist or wet environments. Transmission of the bacteria from horse to horse usually involves direct face-to-face contact or exposure of horses to contaminated feed, water, hands, veterinary instruments, grooming tools and twitches. The disease can also be acquired from exposure to a contaminated environment as long as the organism remains viable. However, a dry environment quickly kills the bacteria.


Strangles is characterized by sudden onset of fever, loss of appetite, painful swallowing, drooling, swelling between the jaw and base of the ear, nasal discharge, cough and abscess formation. Horses usually develop fevers two to nine days before they become infectious to other horses, making isolation of horses with fevers a potential key to limiting the spread of the disease on a farm.


Although the clinical diagnosis of strangles is fairly straightforward, there are advantages to culturing for the bacteria. Such culturing permits a definitive diagnosis of the disease, and an antibiotic sensitivity test will be performed in the lab to aid in selecting the appropriate antibiotic if determined that it is needed. Antibiotic therapy is usually not included in the treatment of strangles because of the inherent risk of developing the generalized form of the disease, known as bastard strangles. Bastard strangles is a more serious, often fatal, disease, compared to the typical case of strangles, which is more of a nuisance than a long-term health threat to the horse.


Antibiotics are sometimes used if:

  • The size or location of the abscess becomes life-threatening
  • Vital signs become compromised
  • Owner insists on antibiotic therapy

Treatment of uncomplicated strangles typically involves monitoring the vital signs, temperature, heart rate and respiratory rate, and treating symptomatically.


The best strategy for your situation, (though by no means foolproof) would be to assume that there are cases of infectious disease at all times, and implement a biosecurity plan to minimize the spread of disease. Such measures include: entry to the show requires a valid health certificate, provided within 30 days; a normal rectal temperature (< 101.0 °F) the morning of the show and upon entry, and vaccination against infectious diseases (this can be determined by the stable, but general recommendations include: tetanus, rabies, EEE, WNV, influenza, equine herpes virus, and possibly also strangles, Potomac horse fever and botulism.)


At the show, perhaps have a designated, experienced, impartial person visually checking all horses upon arrival and if nasal discharge/coughing are noted, take the rectal temperature. If it is a hot day and the horses were on a trailer for more than 30 minutes or so I would not worry about a slightly elevated (101.5-102) temperature but anything over 102 °F should be sent home!


Monitor your horse's temperature for two weeks after the show. If it is over 102 °F when the horse has not been working, call your vet immediately and institute quarantine precautions until the horse is given a clean bill of health.


Where strangles is present the following control and disinfection plans are recommended:


Strangles: control plan

  • Isolate newly-introduced animals for two weeks and observe for signs of strangles or other diseases
  • Immediately quarantine affected or suspect cases
  • Obtain rectal temperatures of in-contact horses twice daily for two to three weeks and separate horses with temperature elevations of 1.5º F or greater
  • Culture recovered horses on three occasions at four-to-seven-day intervals following abscess drainage to determine cessation of shedding. Culture specimens should be obtained from nasal swabs or washes.
  • Prophylactic administration of an antibiotic such as penicillin G should be utilized only in severely affected horses and as recommended by the attending veterinarian
  • Practice good fly control
  • Vaccinate before an outbreak occurs
  • Practice good biosecurity techniques

Disinfection of Equine Facilities


Proper disinfection of facilities is paramount in disease prevention. An appropriate disinfectant should destroy the organisms on the surfaces where they are located. The chemicals effectively used in human hospitals to disinfect linoleum, stainless steel, plastic and glass are vastly different from those used in barns and on horse equipment. Farms have a variety of porous and nonporous surfaces so the disinfectant must be effective in the presence of organic matter in which the majority of pathogens are found. Streptococcus equi, S. zooepidemicus, influenza and herpes virus are present in nasal discharges; Salmonella, E. coli, Actinobacillus and rotavirus are found in feces.


Steam is an effective disinfectant, killing both viruses and bacteria particularly when utilized with a detergent to remove organic debris. Literally hundreds of disinfectants are on the market for veterinary and medical use. Because of their effectiveness in the presence of organic matter, phenolics are recommended for use in horse facilities. Bleach and quaternary ammonium compounds are inactivated by organic matter. Iodophores and chlorhexidine are most appropriately used for hand washing. Formaldehyde, although highly germicidal, is too dangerous for routine use. It is necessary to carefully read the product label to identify the active ingredients. Phenolics can be recognized by the "-phenol" or "-phenate" at the end of the chemical name. Quaternary ammonium compounds are identified by "-ammonium chloride" in the active ingredients. Iodophores contain iodine or povidone iodine. Many different phenolic compounds are commercially available.


When the labor-intensive process of cleaning and disinfecting stalls is undertaken, the most effective germicidal compounds should be used. The most important, and the most overlooked, step in disinfecting a stall is thorough washing of surfaces with an anionic detergent using a steam cleaner to remove as much soil and organic matter as possible. Cationic and nonionic detergents interfere with the actions of phenols. Even the best disinfectants do not work effectively when poured directly on organic debris. Surfaces must be cleaned, rinsed and allowed to dry. The disinfectant should be sprayed on, allowed to dry, and repeated. Contact time with the surface is important to ensure effective germicidal activity. Rinsing off disinfectants is not advisable except when used on feed and water containers.


Besides disinfection of facilities and equipment, isolation of sick animals and use of protective clothing is an absolute necessity. Separate grooming and stall cleaning equipment should be used for sick animals. However, if this is not possible, these items require cleaning and soaking in disinfectant solution for a minimum of 10 minutes. Clothing and towels used on horses should be soaked for 10 minutes in disinfectant solution prior to laundering. Footbaths at the entry to barns and stalls need to be replenished with fresh disinfectant at least twice daily, more with heavy use. Here's a good rule of thumb: if it isn't edible and doesn't move, disinfect it!


Regular hand washing is essential after working with sick animals. Povidone iodine or chlorhexidine hand washing products are best, but alternatively germicidal soap can be used. In instances where water is not available, waterless hand foams, containing >62% ethyl alcohol, are germicidal and can be purchased through human medical supply stores. These products are rubbed onto the skin and evaporate within one minute with no sticky residue.


This answer was written with the help of Sarah Ralston, VMD, Ph.D., dACVN, Rutgers University, Equine Science Center and approved by Nancy E Halpern, DVM, State Veterinarian, Division of Animal Health, New Jersey Department of Agriculture.



What structures are impacted by the surgery for Stringhalt?

I have a question regarding Stringhalt. I am just starting some Connected Groundwork with a 20 year old gelding that has had Stringhalt and had surgery. I have been searching the Internet to try and find where the surgery is performed and what muscles and mechanics may be affected. The horse slightly drags its right rear leg some days, puts more weight on the left overall, but is not terribly stiff, and after some bodywork seems to be improving. The horse will not be ridden; the groundwork and body work is for its benefit. I'd like to properly address this area, and any guidance would be appreciated.



Stringhalt is a peripheral neurological condition that creates an abnormal gait with exaggerated flexion of one or both of the hind legs at the walk and trot. The abnormal gait can certainly create some increased stresses to muscle groups that would not normally be worked that way. Many can become rather back-sore, in my experience. Another reason for the “stiffness” could be discomfort at some other location. I would recommend having your veterinarian evaluate your horse to determine this. However, as for the surgery in question, for true Stringhalt horses, there is a procedure to remove a tendinous portion of the lateral digital extensor tendon as it runs over the hock. This is performed with mixed results.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.



What could a swelling in my horse's stifle be?

I live in Ontario and have a mare that foaled about three weeks ago. The colt has been growing rapidly and we found a large hand-sized lump on its back inner thigh near the patella. I just wanted to know if doing an ice treatment would be a good idea or should we be planning for the worst in thinking it may be a tumor? Please any advice would be really helpful. We are having a hard time finding a vet that is not very booked at least until next month and we are quite worried.



Your concern regarding this lump around the stifle region on the inside of the hind leg is warranted. However, it is difficult to prescribe a course of treatment without evaluating the mass. That is an odd location to have a lump and much of this is dependent on the clinical signs the foal is exhibiting. For instance if this is simply inflammation secondary to it “banging” itself, ice would be an appropriate treatment option. If it is a tumor of some sort, the ice would probably do nothing.


I am curious if this mass is hot, painful to the touch, and if the foal is exhibiting any lameness. Personally I am very aggressive with diagnostics and treatments in foals for several reasons. My one concern is if this swelling is liquid-filled, representing an excessive amount of joint fluid from the stifle. If so, that needs to be evaluated rapidly because of the one concern of a joint/bone infection.


If you cannot get a veterinarian to come to the farm in a reasonable time, you could reach out to the Ontario Veterinary College in Guelph and schedule an appointment as soon as possible. There is also a relative large veterinary clinic in London as well as by racetrack outside of Toronto.


This answer was written by Michael N. Fugaro, VMD, Diplomate ACVS, Associate Professor of Equine Studies, Centenary College and Adjunct Professor at Rutgers University.


What are the risks associated with treating allergies with steroids?

I am currently housing a mare that is severely allergic to bug bites, particularly mosquitoes. The owner keeps the mare as bug-free as possible, with fly spray, topical ointments on hives that have been itched open, and cover-everything-you-can fly sheeting. She also treats hive outbreaks with benedryl on a regular basis. This is usually sufficient to get her as far as mid-July or even mid-August, but at some point, the mare’s immune system seems to reach the breaking point, and her owner has to go to steroid treatment to keep the outbreaks and itching under control. This has been the pattern for 3 years and she has gone to the steroids once again, on the advice of her veterinarian. Our greatest fear is that the steroids will bring on laminitis, and the mare will have to be put down. On the other hand, she can’t have a very good quality of life if she is allowed to tear her skin off, which she would certainly try to do, without treatment. So my question is what are the risks of the steroid treatment? And are there cumulative effects to consider, as the same pattern repeats, year after year?



This type of allergic horse can be particularly vexing. Some people do not have good luck with Benadryl in preventing chronic allergies in horses. Some horses do well on hydroxyzine (an antihistamine) in late spring and stay on it until late fall. This does not stop the outbreaks of hives, but it does decrease the number and severity of episodes. There are also some horses that do not respond, and live on antihistamines and steroids during that time of the season. This type of immuno-therapy takes about a year to really prime the immune system to see any results, if any. These shots are not the panacea but can be worth a try to minimize other drugs. Owners can also consider determining the specific allergens responsible for the reactions and treat the horse with the desensitization allergy shots.


So to answer your question regarding the usage of steroids and complications such as laminitis, unfortunately we still do not understand the reason why steroids induce this complication. Laminitis secondary to corticosteroids appears to be unpredictable. Some horses may develop it after one treatment, while some may be treated for years and never contract laminitis. So we cannot say that there are any cumulative effects of steroids; however, the longer a horse is receiving steroids, the higher the potential for having an episode.


Other complications associated with steroids usage mirrors Cushing’s disease in horses, which is when the horse overproduces natural steroids secondary to a pituitary gland tumor. Some of the clinical signs are curly long hair coat, pot-bellied appearance, dull hair coat, and thinning of skin. When considering prolonged steroid administration, you will have to weigh the options with the consequences. Is the horse’s comfort level worth the risk? This is something you should discuss with your veterinarian in order to make a decision.




How do I prevent ulcers in a race horse?


I know that most racehorses get stomach ulcers. How can I prevent ulcers without using a pharmaceutical product?



The best way to prevent ulcers is by changing management practices. Two key practices will help:


  1. Provide free choice, good quality hay. One of the major causes of ulcers is the constant supply of gastric acids naturally present in the horse’s stomach. With hay freely available, a horse can continuously have something in its stomach to help buffer the acids.

  2. Provide as much turnout as possible. Another major cause of ulcers in horses is stress. Increasing time outside helps decreases the horse’s stress level.

Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.



My horse is urinating excessively and dribbling urine; what tests can I do to find out why?


My 15 month old warmblood/TB gelding is urinating excessively and dribbling urine constantly. My veterinarian tells me not to worry as he has no clinical signs of illness (no fever, not listless or dull, not off his feed, no discoloration or unusual smell of his urine). I am most concerned about the urine dribbling between urinations. I have already asked about UTI, hypospadeous, and a bean (I haven’t felt any). Are there any tests we should run to further evaluate this condition?



If your horse is incontinent and thus constantly dribbling, there could be a few diseases of concern. Equine Herpes Virus is one disease that can have this complication remain as a residual after the infection is cleared. However, there are other diseases to consider such as a urinary tract infection or bladder/kidney stones.


The excessive urination can be rather seasonal in some locations. Some horses will saturate their stall in the winter only. When tests are run, no reasons for the activity are found. However, some diagnostic tests can be considered for your horse.


The first recommended diagnostic is to perform a serum chemistry profile and a urinalysis. Depending on the results of these tests, a urine culture can be considered. Further evaluation of the urinary tract can be performed with a rectal examination and ultrasound of the bladder and urethra. One can also perform a cystoscopy (pass a camera up the urethra into the bladder). Be forewarned that after performing all these tests, results may still be inconclusive. However, under the circumstance described, some of these tests may be warranted. It is best to work with your veterinarian to decide which tests are most appropriate for your horse. Also be aware that some of these diagnostics can incur expense.



My horse has high blood levels of Vitamin E; is this a problem?

My horse is a 15-year-old Quarter Horse gelding that is used for English riding and light jumping. About a year ago he had muscle soreness, stiffness, poor performance under saddle, and difficulty with his hind legs while being shod. He was looked at by a vet using Nuclear Scintigraphy, with no significant findings. He has also tested negative for Lyme disease on multiple occasions.


We recently tested him for levels of vitamins E, A and Selenium. The results showed an elevated E level, a low A level, and a selenium level within normal range.


We made some adjustments to his saddle and initiated a high fat diet with a high vitamin E supplement. The horse is currently doing extremely well, looks very good clinically, and has substantially improved with his hind legs. However, we are concerned regarding the high E level. Should we specifically supplement this horse with vitamin A?



It all depends on what level of E you are giving. I usually recommend that horses with muscle problems be given a 5000 IU/day supplement of E. (Watch that selenium is not increased this much as well.) Studies have shown that groups of horses given vitamin E supplements of 10,000 IU/d had decreased beta-carotene levels compared to groups of horses given a lower (5000 IU/d) dose and control groups (not given a supplement). The levels of beta-carotene were not shown to be deficient (as no deficiency level has been determined), but they could eventually affect vitamin A levels.


I would try to see if your horse could go with 5000 IU/d and still maintain his soundness without muscle problems. If your horse needs 10,000 IU/d of vitamin E, I recommend making sure he consumes good quality pasture or gets a beta-carotene or vitamin A supplement.


I would also consider asking your vet to take a muscle biopsy and test for Polysaccharide Storage Myopathy (PSSM). It sounds like he might have a mild case since he responded so well to the high fat and high E supplementation.


Answer provided by Carey Williams, Ph.D., Rutgers Cooperative Extension.


Is there a treatment for windpuffs?


I have a mare with a windpuff on the outside of her hind pastern/fetlock area. What is the best treatment for windpuffs?



Windpuffs, also known as windgalls, are swellings of the flexor tendon sheath on the back of the fetlock region. This is caused by inflammation of the synovial membrane (inner lining of the tendon sheath), which in turn, produces more fluid. It is very common in the hind legs of performance horses. In many cases, these are cosmetic and do not appear to have a clinical effect on the horse’s performance. In cases where clinical signs occur, injections within the tendon sheath can decrease the inflammation. It is difficult to decrease the swelling of windpuffs with topical therapies, wraps, poultices, or even oral anti-inflammatories, but their usage is warranted. You should consult your veterinarian on the clinical significance of windpuffs on your individual horse and the therapeutic options.


Can lime prevent my horse from getting White Line Disease?

I am trying to figure out why, since moving to Texas, my horses continually contract White Line disease. I have fed numerous supplements, used various topical medicines and changed feed all to no avail. I finally had my soil analyzed and found it is very acid, 5.5%. I broadcast garden lime in the pasture and found improvement for a year or so. What is the pH balance of a horse hoof? If White Line is a bacteria or fungus then it stands to reason that lime would kill it, right? I just don’t know what pH I should be shooting for when applying lime.



The etiology of White Line Disease is truly not known. Unfortunately the literature is very confusing and filled with anecdotal information primarily. Much of this answer is opinion only and not scientifically based. Many veterinarians feel that the disease has a bacterial, fungal, mechanical, and an environmental component to it. It seems that some horses are significantly prone to the disease, especially during certain periods of their life. While some horses get a more superficial distribution of the disease on the hoof, others are deeply seated within the white line. There are a host of topical therapies out there with no strong evidence of effectiveness. Some cases appear to clear up with a topical therapy, while more severe cases require hoof wall resections. Some mild-moderate cases can respond to more frequent trimmings of the hoof. It seems likely that with the more superficial “infections,” any change in environment will help. You can change the salt concentration, the pH, or even the moisture content, and affect some cases in a positive direction. I don’t know if this is what you experienced with the lime. I have never treated the disease with lime. But again, if it made a difference, I suspect it was a relatively superficial distribution of the disease.
As for your question regarding the pH of the hoof, I don’t know that this has been completely characterized. I have not seen anything in the literature providing that information; however, it is possibly out there. In order to appropriately answer that question, you would need to take tissue samples at different depths of the hoof. The outer part of the hoof is made up of cornified tissues which are dead cells highly concentrated in keratin. If I had to guess, the pH on the surface would equal the outside environment. Also, as you move deeper within the hoof, closer to the coffin bone, the pH would probably mimic the physiological pH of the biological system of 7.4. Again, this is only speculative, and a thorough research study would be required to state one way or another.



How do I treat white spots on a horse’s face?

My 3-year-old Quarter Horse developed "bleach spots" on her face. A friend of mine saw them and said that this was some type of mineral deficiency which is easily corrected with a supplement. I'd like to get the color back in these spots. Do you know what this supplement might be?



Loss of pigmentation sometimes does respond to supplementation with copper and zinc, though there are several other causes that are not nutritional. If your horse is on a good commercial concentrate and has a trace mineral block I would doubt if it were a copper/zinc deficit. Loss of pigmentation also is more common in Arabians than Quarter Horses. There is a genetic disorder in some breeds, of which the Quarter Horse is one, that can cause a "spidery" loss of pigment on the body, but that is not usually restricted to the face. If the horse is on only minimal grain and locally grown hay or pasture (southern New Jersey's sandy soils tend to be deficient in certain minerals), you could try using a trace mineral supplement. There are lots of supplements out there-read the labels and pick one that would provide 15 to 30 mg copper and 60 to 100 mg zinc per day for a few weeks to see if it helps.


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.







The material provided on this site is for educational purposes only and is not intended to diagnose, prevent, or treat any illness. Any recommendations are not intended to replace the advice of your veterinarian. Any products mentioned are not intended to diagnose, treat, cure, or prevent disease. Mention or display of a trademark, proprietary product, or firm in text or figures does not constitute an endorsement by the Equine Science Center or Rutgers University and does not imply approval to the exclusion of other suitable products or firms.







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