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My horse's hind leg locks up. Could it be an abnormally locking patella?
Can a horse with anhydrosis (lack of sweating) still be ridden?
What causes a horse to drool excessively?
My horse lost an eye. How do I get started with her again?
My horse has a poor hair coat, is this a nutritional issue?
What causes headshaking?
What is HYPP? Should bananas be fed to horses?
How effective is acetazolamide in the treatment of HYPP?
Do horses get Lyme disease?
I think my horse has a neurological problem. Can you help?
What is ringbone or sidebone?
How can I tell if my horse has ringworm?
My horse just passed a stone! Does he need more water?
How do I prevent ulcers in a race horse?
My horse has high blood levels of Vitamin E; is this a problem?
How do I treat white spots on a horse’s face?

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.

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.

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.

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

“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)

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.

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.

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.

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? 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.

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. A licensed, effective vaccine for Lyme disease has not yet been made available in New Jersey. There is a vaccine available to all 49 other states, but its efficacy has yet to be determined.

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

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.

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.

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.

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.

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:

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.

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 Dr. Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension.

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