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Disorders & Diseases



My horse is allergic to oats and grass hay. What should I feed him?

I just had a blood test for allergies done on my horse. He tested positive for oats and beets as well as rye, fescue, orchard grass, brome grass, reed canary, and borderline for timothy. We will probably give him alfalfa hay, but do you have any suggestions for the type of grain he should get?


My exact answer to your question would be based on what you use your horse for - i.e., what is his activity level - and what his body condition looks like. Does he keep weight on easily, or is he a hard keeper? The reason I ask is because if he doesn't need a high energy feed he would do well on rolled barley top-dressed with a vitamin/mineral supplement. If he needs more energy you can add non-stabilized rice bran. You don't need to add extra calcium if feeding alfalfa. Finding a company that produces a sweet feed without oats will be quite a challenge.


Your other option is to find a feed mill or nutritionist in your area that will work with you to formulate your own feed. You could ask the mill to make you a pellet or textured mix without the things he is allergic to and then have it balanced with a vitamin/mineral premix. Just make sure that any feed you have made is low in protein and calcium, since the alfalfa you will feed will supply all he needs.


Feeding straight grain will probably be more cost effective than going with a specially formulated pellet. If you find that you have to feed more than 2 lb of barley per feeding to maintain his weight then I would recommend rice bran. It will probably cost a bit more, but you can significantly cut back on the barley when you add this. Remember, with horses you always need to make dietary changes slowly! So, if you plan to add or change anything, try to do so over a period of at least 2 weeks.


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



What can I feed my horse that is allergic to oats and wheat?

I have a 15 year old Holsteiner horse that was just allergy tested. According to the results, he is allergic to oats and wheat. Can you recommend a feeding regime which would exclude those two components while still providing enough nutrition? He is a working competition sport horse (Jumper/Equitation)?


There are several options for a horse that is allergic to oats and wheat. First, one can find a feed mill or nutritionist that will formulate an individualized feed. The mill can make a pellet or textured mix without the things the horse is allergic to and then have it balanced with a vitamin/mineral premix. However, this may be expensive and time consuming.


If a commercial feed that does not contain these two ingredients is unavailable, feeding straight grain will probably be more cost effective than going with a custom formulated feed. Corn or barley can be a good substitute for oats, but be aware that corn has much more energy than barley. If it is necessary to feed more than 2-3 pounds of barley per feeding to maintain the horse’s weight, try adding rice bran as a fat source. Add up to 1-2 lbs of calcium fortified rice bran per day, and it will help maintain weight and manage energy level when being ridden. Vegetable or corn oil can also be used to provide more calories, though they are devoid of any other nutrients. A daily feeding of up to one cup per day, divided into several feedings can help maintain optimal body condition. Remember, make dietary changes slowly! So, if planning to add or change anything, try to do so over a period of at least two weeks.


Another important rule is to never forget forage. Horses should consume a minimum of 2.0% of their body weight in forage, whether it is hay, pasture or other source. A good grass hay is probably what your horse needs; however, if it is picky with hay consumption or the hay is not of good quality, feed an alfalfa mix or supplement with some alfalfa cubes or pellets during meals


Since it is a competition horse, balance out the straight grains and hay ration with a general vitamin and mineral supplement selected to complement the grains/hay chosen. Most commercial horse feeds that contain oats already have a premix in them, so if one decides to feed straight grains, provide this supplement separately. One may want to consult with a nutritionist to determine a horse’s needs.




Are there blood tests to determine mineral deficiencies?


Are there blood tests for horses to determine if they are low in specific nutrients such as magnesium or calcium or chromium, etc.? There is so much "advice" on the Internet suggesting giving one nutrient/supplement or the other to horses for this or that reason.  And I am aware that, just as in humans, giving a nutrient that isn't needed can cause problems as bad as, or worse than, a deficiency of that nutrient. I would like to determine whether my horse really needs something before adding it to his diet?




Blood calcium and magnesium concentrations do NOT reflect dietary intake. One can only determine adequacy by analyzing the feeds and supplements in the ration. There is no proven requirement for chromium in horses and it can be toxic if given in excess. It has not been scientifically documented to alter glucose metabolism as claimed on the Internet. Based on controlled, scientific studies performed in the late 90's, the "recommended" doses of chromium might actually impair immune function, even in insulin resistant horses.


Similarly, magnesium supplementation has never been documented to alter insulin sensitivity and, contrary to popular belief, is not innocuous if given in excess. In a survey of feeding practices on the east coast in the early 90's, I found that NO farms were feeding rations deficient in magnesium but several were in excess of recommended concentrations-and had an increased incidence of developmental orthopedic disease!


The best way to determine if your horse needs supplementation is to carefully read the labels of the feeds and supplements you are using and get an analysis of your hay and pasture. If you want help in evaluating your horse's ration, contact an equine nutritionist with all of the pertinent information (age, breed, use of the horse, clinical signs you feel are a problem, amounts and nutrient analysis of all feeds/supplements, exercise regimen, pasture access, feeding regimen, etc.).


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



How should I feed my diabetic mini stallion?

I have a miniature stallion that has chronic laminitis/founder. In the past, a trim plus supplements like devil's claw and others (and a lot of TLC!) would bring him out of it only to have him suddenly lame again. My veterinarian suggested that he might be diabetic/insulin resistant and not able to process sugar. I was feeding him plain oats, a few carrots, and alfalfa hay. He has a pretty laid-back life - little exercise, etc. other than playing in his pasture with a jolly ball. His pasture is mostly weedy and is kept cut down. Is there anything else I should do for him?


I assume the mini stallion is in good body condition. If he is overly "plump" (fat pads around his tail, ribs not easily felt) that could be contributing to his problem. If he is fat, put him not only on a starch-restricted diet but also one to reduce his weight. You should be able to get good grass hay - I'd switch him to that instead of the alfalfa. Give him 2% of his body weight per day divided into two or three feedings, and make sure he has free access to salt and water. Assuming he is mature, you should not need other supplements. If you feel you have to give something, I'd suggest maybe 4 ounces of a low starch grain supplement or soaked beet pulp without molasses twice a day. You said the pasture was predominantly weeds, but that it is mowed. Frequent mowing will increase the carbohydrate content of the grasses present and encourage clover, which will contribute to his problems. You might try using a grazing muzzle when he is out


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


How do I feed a rapidly growing foal with epiphysitis?

I have a foal that was foaled on Feb. 16, 2005; he has epiphysitis. His dam is ½ Clydesdale, ¼ Thoroughbred, ¼ Hanoverian. I noticed a swelling above his left hind fetlock not long after he was gelded, at 2 months. When the vet came out to check it a couple weeks later, it was bigger, and the other hind was starting. I was feeding them a Mare & Foal feed, small hay cube mash, grass hay, and a molasses/mineral bucket; the vet said to withdraw all grain immediately. Currently, the swelling is not at all reduced, has increased on the right hind, and has started somewhat on the left front. Since he was weaned he has gotten quite lean, with some ribs showing, backbone a bit elevated, and a bit of hay/grass belly. Is there anything else I should be feeding or not feeding, doing or not doing?


It is pretty common for foals to have epiphysitis. The ration you had him on originally was perfectly fine. In fact, grass hay alone is probably too low in protein and minerals to meet his needs. This is most likely the cause of the epiphysitis, not an excess of protein and minerals. Right now his appearance and calm attitude are due to a lack of calories and protein. You are at risk of stunting his growth by keeping him on his current diet. However, any dietary changes will need to be made very slowly because if you improve his diet too quickly he will get a compensatory growth spurt that could cause problems.


He should be on a grass/legume (either alfalfa or clover) mix hay or free choice pasture, and fed a concentrate formulated for growth, like the Mare & Foal you had him on, up to a total of 6-7 lbs per day divided into 2 or 3 feedings. He should also have free access to salt and water. A plain white salt block is fine. However, do not start him on the concentrate too suddenly since he has had none for a while. I'd suggest giving only ½ lb per feeding for 2 or 3 days, then increasing by ½ lb per day until you reach the desired intake. Same with switching the hay; give only a pound or two of the new hay with the grass hay he is used to and gradually switch over. If he starts to get upright in his pasterns, back down to a slightly lower level for a few days and then gradually start increasing again. Do not discontinue the hay completely. The more turn out and free exercise he can get, the better.


The idea that epiphysitic foals need to be starved and put on low protein diets has been repeatedly disproved by research over the past 15 years. Refer to the fact sheet “Feeding the Rapidly Growing Foal” for more information on this topic.


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


How do I feed a young horse with epiphysitis without starving him?

I have a seven-month-old Andalusian colt. He was fed commercial sweet feed and alfalfa hay when he was about three months old until he came to me at five months. My trainer and vet took one look at him and told me to only feed him grass hay for the next four months. He had horrible physitis and hot, swollen joints. He would lie down all the time and just looked unhappy. I have fed him grass hay now for about a month; he is no longer swollen and runs around like a "normal" horse. However, he is terribly skinny! He is now getting one pound of a 12% protein feed and grass hay daily. I just don't know if this is enough for him. Please help!


Your trainer and vet had you bounce the poor colt from one extreme to the other. He was probably overfed initially, but now he is severely deficient in both protein and minerals and is at even greater risk. The challenge now is to get him back on track without a serious compensatory growth spurt.


I would strongly suggest switching his concentrate to a restricted starch product balanced specifically for growing horses. These should have 14-16% protein. (Remember to read your feed tags!) Whichever brand you choose, do not use a sweet feed with added molasses.


Start him at 1 lb twice a day and slowly switch him onto an alfalfa/grass mix hay by adding ½ a flake each day. He needs the extra protein and calcium in the alfalfa. If you can not get a good quality mixed hay, add 1 to 2 lbs of timothy/alfalfa cubes to each feeding. Increase his concentrate intake by a half pound every 2-3 days until he is getting about 3 lbs twice a day. The biggest risk is that he will start to grow very rapidly and start to get upright in his pasterns. If that happens, cut the concentrate feedings in half but do not starve him.


For more information on young growing horses please see our “Feeding the Rapidly Growing Foal” fact sheet.


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



Is there a good forage substitute that can be fed to a horse with diarrhea?

I have a Lipizzaner gelding that gets diarrhea on all hays we've tried with the exception of timothy. We ruled out sand in the gut, parasites, teeth, and I doubt it's mold. We think he just needs a high-fiber forage, as he is true to his breeding and a very easy keeper. Also, his stool will return to normal on days I feed him psyllium seed. I keep him at a boarding stable, so I don't have personal control of his forage. Recently the price of timothy hay has gone through the roof, so now most of the barns around here have switched to orchard grass hay. The new hay is properly cured and stored, but very tender and soft with few tough stems. After the switch, my horse has had loose stools.


He gets no grain except for a mini-ration of a high-fat commercial feed on days that he works hard. He also gets a light vitamin supplement in a few timothy pellets. He is very healthy and energetic, and is on a regular dental and worming schedule. I would like to find a forage replacement that is high-fiber and convenient to feed with a scoop. Any suggestions?



If he seems to do better when fed psyllium, you might try to just keep him on that. I know of no detriment to feeding it daily. There are very few forage substitutes that could easily be managed in a boarding situation and keep him healthy and sane. Three to four pounds of beet pulp fed 3 or 4 times a day might be an option, but it would have to be the type that does not contain molasses. Beet pulp would also require supplementation as it is not a "complete" feed, lacking in vitamins A, D and minerals. Most people feel more comfortable feeding it soaked, which is labor-intensive, but it does not have to be fed this way.


Have you had him allergy tested? Perhaps there is another hay that he could tolerate. Have you tried him on alfalfa? It can be harvested late in its growing season so as not to be so high energy and protein. There are timothy/alfalfa cubes that could be fed dry and basically free choice, which might be a good management-free option. The timothy pellets alone would not give him enough "chew time" to keep him happy, unfortunately. However, the other more obvious option would be plain timothy hay cubes without the alfalfa. These might not cost as much as actual timothy hay.


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



How do I get a foundered horse to start eating again?

My horse foundered 8 days ago. He is not really doing well at all. I have been giving him Bute and Banamine as needed. A veterinarian is attending to him. However, he is not eating hay or feed. I have tried Equine Senior and oats. He is not interested in grazing. He just started walking a little better but is still on drugs. On my vet's advice, I tried a product supplement for digestive problems along with 60 cc of Maalox because of the Bute. After 4 days, he ate a handful of feed but still will not eat hay. Do you have any suggestions?


Your concern about him not eating for 4 days is valid. The phenylbutazone (“Bute”) could be contributing to gastric ulcers that would be also brought about by the stress involved. If the pasture was "stressed" (e.g.: went for a prolonged period without rain or was overgrazed) or the horse is overweight, this could have led to him foundering. If he is overweight I would be even more concerned, because prolonged "starvation" in a fat horse can cause liver damage.


I would try a bran mash. You can chop up carrots or apples to put in the mash; this usually stimulates eating. If he will eat the pelleted feed you typically use, I would strongly suggest changing over to one higher in protein, fiber and fat and lower in carbohydrates than the Equine Senior. Initially, you want to feed small amounts (1 or 2 lbs per feeding) at as frequent of an interval as possible (at least three times a day) if you do find something that he will eat.


The fact that he won't even graze is especially worrisome; you could try hand picking grass for him and feeding it in his stall. It might be too painful for him to graze on his own. People are typically afraid of alfalfa in a founder-prone horse, but a handful of alfalfa pellets three or four times a day also might help him regain his appetite.


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



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 can I feed my horse with HYPP and PSSM?


I have an 11 y/o QH gelding who has acute rhabdomyolysis and renal failure. We were able to get him through the acute phase of his disease. Diagnostic testing revealed that he is negative for Hyperkalemic Periodic Paralysis (HYPP), but he shows some clinical signs of the disease. A muscle biopsy shows he is positive for Type 2 Polysaccharide Storage Myopathy (PSSM). Since the recommended diets for these two disorders are contradictory, I'm having a hard time figuring out what to feed him. Do you have any suggestions? He's currently on acetazolimide and a grass hay diet with a 12% protein commercial feed as a supplement.



Actually the recommendations are not all that different! For the HYPP you want to restrict potassium; for the PSSM, restrict the sugars and starches. Soaking his grass hay in warm water for 30 minutes before feeding will leach out potassium and sugars, especially if he is fed a chopped hay product. (There are several out there; avoid those with added molasses). Feed no more than 7 to 10 lbs per feeding to prevent it from molding, and discard any leftovers before feeding more. He'll probably need at least 3 feedings per day.


If he needs extra calories to maintain his weight/condition you could use corn or vegetable oil by pouring ½ to 1 cup over his hay each feeding. Make sure to add it slowly: start with about an eighth to a quarter cup and increase it over a week. The oils have no potassium or sugars. Rice bran and unmolassed beet pulp, both of which are relatively low in both potassium and sugars, can be mixed 1:2 by weight (e.g.: .5 lb bran to 1 lb beet pulp) and soaked in water as another fairly safe energy/protein/mineral type supplement. The oil could be added to that mixture too if extra calories are needed.


Just avoid any alfalfa or soy meal -based feeds, which are high in potassium, and straight grains like corn or barley or sweet feeds, which are high in sugars.


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



How should I feed a horse with HYPP?


I have a mare that has been diagnosed with HYPP N/H and has shown mild symptoms since I have owned her. I am trying to alter the diet to reduce potassium levels. I am currently feeding orchard grass hay with 2 lbs of a low starch pelleted feed morning and night. I also feed a mid-day meal of oat hay and some soaked beet pulp/wheat bran mix. The mare gets daily turn-out and I trail ride her about three to four times weekly. I have been told that adding corn syrup to her am/pm feedings would help eliminate any future attacks. Can you please let me know if there is any harm in adding corn syrup to my mare’s daily diet? Also, any recommendations you can provide would be greatly appreciated.



It is highly recommended to stay away from any form of feed that contains molasses, which is very high in potassium, and just use pure grains (e.g. oats, barley, corn, wheat, etc,) with beet pulp. The oat hay is appropriate; however, timothy and bermuda grass hays are the best in this case. As for the corn syrup, it will potentially help reduce the severity of the episodes. Theoretically, the rapid increases in blood sugar from these grains or the corn syrup will help drive potassium into the muscle cells, preventing the peaks in blood potassium which cause the clinical attacks. However, these have not been research tested, and only have been speculated to help. This is due to the insulin-mediated movement of potassium across cell membranes. You can use small amounts of the syrup on top of the grain meal without harming the horse.


Other recommendations are to stay away from feeds high in potassium like alfalfa, orchard grass, brome hay and soybean meal, kelp products, and molasses. Also, it is recommended to develop a feeding routine that splits the daily ration into 3 to 5 small meals per day. The theory here is to keep the potassium intake as low as possible in each meal. Horses should have a daily ration between 0.6 and 1.1 % potassium, but ideally meals should contain < 33 g of potassium total. Avoiding exercise for the first three hours after a meal is recommended.


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



What is causing my horse's runny stool?


I have a 20 year old Arabian mare that continually has loose stools. Often before she defecates she expels a watery substance that is usually greenish in color, with no particular abnormal odor. She also is particularly difficult to keep weight on. I have tried changing her feed and am no longer give her alfalfa. I give the mare about a 10 -12 inch flake of Bermuda grass hay twice a day with several supplements, (e.g. 2 lbs high fat supplement, 4 lbs an equine senior feed, 1 lb of a balancer pellet, a probiotic, and because I have a new foal from another mare I give her 6 lbs/day of a mare/foal feed). She seems to be maintaining her weight on this regimen, but she continues with cow pie stools and this watery squirt that accompanies defecation. I have tried timothy grass, orchard, and other mixes, sometimes it appears that things that I have tried work for a while and then cease to be effective. Do you have any idea what could be causing this, as I believe it is affecting her weight as well and it is getting very expensive?

First of all, does the mare have access to sandy soils and overgrazed pasture or is it fed in a paddock with sandy soil? If the mare is on sandy soil, what you describe is a classic sign for sand ingestion. Collect a handful of the mare’s feces and put it in a jar of water. If a layer of sand filters out to the bottom, look into getting her on a regimen of a Psyllium product designed to help eliminate sand. Consult with your veterinarian regarding doses. Try to prevent future ingestion by putting rubber mats under the area where she is fed and using a hay feeder that has a catch basin to keep hay off the ground. Also get her teeth checked for sharp points and hooks, especially at the back of the molars that might be making chewing difficult and affecting her ability to keep weight on.

Regardless of what the results from the above are, you are over supplementing this mare and that, in itself, could be the cause of the problem. Discontinue the probiotics; they are not helping and maybe contributing to the loose stools. The mare/foal feed is unnecessary. The high fat supplement you are using is redundant to the balancer pellet in its mineral and vitamin content and therefore should be discontinued as well. Assuming your veterinarian has not find evidence of liver or kidney problems but does detect pituitary dysfunction, which might be part of her problem, switch her to a low sugar, high fat feed; there are several on the market. Start by taking out one pound of the senior feed and adding one pound of the new feed each day at each feeding until completely switched. If you add a meal of two or more pounds per day (so she'd get three meals, two pounds each) plus the one pound per day of the balancer pellet I think you might see a difference. However, if kidney or liver problems are detected we will have to explore another route.


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



What can I feed a toothless horse?

How do you get 15 lbs of roughage into a toothless horse? I have a Paso Fino/Quarter Horse gelding in his twenties. He should weigh 1100 lbs. I am presently feeding 7 lbs of a pelleted grain mix and 4 lbs of 10% protein sweet feed.



The best way to get a horse with bad teeth to eat anything, especially roughage, is to feed hay cubes. You can purchase grass, legume or a legume/grass mix cubes. I recommend straight grass hay cubes for your horse. They can be fed with water so they break down and turn into a mash. You can actually add all of his feed to this mash, sweet feed included.

However, if he has no teeth at all, I would recommend switching your sweet feed to a pelleted, or, better yet, an extruded feed that you can add to the water and cubes for a total mash. Beet pulp and rice bran are also good additions to the diet. Rice bran is high in fat and can help him gain weight. Beet pulp is high in fiber, so if he doesn’t like the hay cubes, add beet pulp to the wet mixture. Remember, when feeding moistened feed, always weigh out what you are feeding before adding water to it!


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



What could cause my combined driving horse to tie up?

Irecently experienced an incident of tying up in my young combined driving horse. It’s not a dramatic incident that would be obvious, but a more subtle one that affected his movement and willingness to work. He has been "just not right" since his last competition four weeks ago. We are trying to figure out if this was the result of a particularly harsh marathon in the hills, or if this is dietary, i.e., diet too high in carbohydrate, deficient in selenium, etc. - or both! He is an "easy keeper", a 15 hand Welsh Cob.


If I understand what you mean by "not right", I would say he is a little muscle sore. This could have been from the intense work he just had, but if you have never had this problem, it is a bit strange (depending on how old he is). I have a couple of suggestions, but for a more detailed response I need to know more about his diet, i.e. how long and what kind of pasture is he on, what kind and how much hay do you feed, and is he on any other supplements?

I would recommend a high fat feed (at least 10%), with higher fiber content (>10%). Since he is an easy keeper, you shouldn't need to feed more than 2 to 3 lbs. for your horse.

Make sure he is on good quality grass hay, especially if he is on limited pasture. The one supplement I would try after deciding on a feed is a Vitamin E supplement. I have found good results with higher levels of dietary vitamin E corresponding to lower levels of muscle enzyme leakage and muscle soreness. These commercial feeds have plenty of selenium in them so I would aim for a vitamin E supplement that is pure and does not contain selenium. VitaFlex makes one that is concentrated, so you only feed a little with his small amount of grain. Start with 2,500 IU/day and if you don't see a difference in a month, or if he gets worse, raise the dosage to 5,000 IU/day.


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



How do I feed my racehorse that suffers from "Tying-Up"?

We have Standardbred racehorses. Recently, our 4-year old mare tied up. Her muscle enzyme count was 13,000. Is this going to be a permanent problem with her muscles? Because of this incident we are in the process of changing our feed. We have been feeding oats, sweet feed and alfalfa hay. We are going to change the oats and sweet feed to a feed formulated with very low carbs and sugars. We have had some feedback that suggests that the racehorses need the soluble carbs found in grain as an immediate energy source. Do you feel that the oats are a necessary part of a balanced diet or not?


When muscle enzymes, which are used to perform reactions in muscles, are found at high levels in the bloodstream, it means that they have somehow escaped from the muscle cells. Usually this occurs when the muscles are damaged by the process of tying-up. Scientifically speaking, the muscle membranes are ruptured and the cell contents leaks out into the bloodstream. This is not a long-term problem because muscles can repair themselves quite quickly; the horse may just be sore for a little while (kind of like when our muscles hurt after strenuous exercise). If the horse keeps tying-up it may become harder or take longer to repair, but usually one episode will not cause permanent damage.


Most low carb feeds have high levels of fiber, which is considered a “structural” carbohydrate. However, because fiber is slowly fermented in the hindgut of the horse, it is not metabolized in the same way that “soluble” carbohydrates are. Soluble carbs, i.e. sugars and starches, are digested in the small intestine. If they are overloaded, they will rapidly ferment in the hindgut.


That said, it is the overload of sugars and starches you want to avoid, such as your high-energy feeds and sweet feeds (e.g. corn, molasses, etc.). Oats, on the other hand, are not high in starch, but in fiber, so they will not be the problem here.


Some low carb feeds not only contain high levels of fiber, but are also formulated to have a high energy content. If so, they will have high levels of fat added to replace the energy lost by removing the starch. Check the feed tag of the feed you are using. It should be around 10% to 12% fat for racehorses. If it is lower than that you can still feed it if you want, but I would recommend adding another fat source to boost the energy content of the diet. You can do this using a vegetable oil or rice bran. You can add up to two cups per day of vegetable oil, but break it over three feedings. I like rice bran the best because horses love the taste and it is also high in fiber along with fat. Most companies will have a rice bran product. You can just feed it as per the directions on the bag.


Another component I recommend adding to the diet of a tied-up horse is vitamin E. Especially in racehorses, vitamin E has been shown to help decrease the amount of muscle damage due to intense exercise. I recommend a pure vitamin E product with no other added components (like selenium). You can feed up to 5,000 IU per day to an exercising horse. Just look on the label of the product to see how many IUs there are per ounce of the product and feed accordingly.


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



My mare has ulcers. How should I feed her?

I own a 7-year-old Oldenburg mare. She is currently being treated for ulcers with GastroGard® and I'm trying to determine the best feeding program for her. I have been told that horses with ulcers should have alfalfa hay--but alfalfa is high in calcium and could cause an imbalanced calcium/phosphorus ratio. How should I feed my mare, and should she have additional supplements once she finishes her course of GastroGard®?


Alfalfa has been reported to be a good feed for horses with gastric ulcers due to the potential "buffering" effect of its high mineral content and protein. The higher calcium would not be a problem for your adult mare. However, because of its higher digestibility, if she is stall bound or in limited turnout work you would not be able to feed it free choice. An increase in training along with moving barns may contribute to persistence of the ulcers, but I would stop the GastroGard® once she is on a regular schedule and see if the new diet and routine help. Other supplements are not needed if your horse is maintained on good quality hay. If she is fed grain, try and stick with something that is not only high in fat, but has additional fiber as well (>10%).


Answer provided by Sarah Ralston, VMD, Ph.D., dACVN, Rutgers Cooperative Extension. Where trade names are used, no discrimination or endorsement is implied.





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