Ask The Vet: Nutritional Supplements - March 09

Good for you for rescuing these two horses! From my background in the humane world I know firsthand how rewarding yet how challenging this work can be. For a detailed explanation of how to safely bring a neglected horse back to health, I invite you to read the article “Saving Survivors,” which originally appeared in the April 2003 issue of The Horse magazine and can be found at www.thehorse.com/ViewArticle.aspx?ID=4283.

Here are the steps I take when working with debilitated horses:
1. Quarantine the rescued horses for at least two weeks (preferably four) to protect the existing herd and to reduce stress on the new arrivals.

2. Have a veterinarian perform a complete physical examination on the rescued horses including an oral exam, bloodwork, fecal exam and any other diagnostic tests that are necessary such as X-rays or ultrasound.

3. Introduce food slowly and carefully following Dr. Carolyn Stull’s guidelines if the horses are a body condition score of 3 or less on the Henneke scale or if they have been completely without food for more than a few days to avoid “refeeding syndrome.”

4. Deworm when your veterinarian thinks the horses are healthy enough to undergo the treatment. Avoid products containing moxidectin, which should not be given to debilitated horses and products containing pyrantel, which are fast-kill dewormers. Start with a benzimidazole and follow up with ivermectin.

5. Unless there are serious medical problems in the mouth or with the hooves, wait to float teeth and trim feet until quarantine is over and the horses have begun to gain wait. Ditto for vaccinating. These are all stressful procedures for rescued horses that need to devote all their energy to rebuilding tissues.

6. Begin grooming, handwalking and other normal handling after quarantine is over to reduce the risk of spreading disease to the rest of the herd and to keep stress at a minimum for the rescued horses.

It takes at least two weeks to see weight gain (or loss) in a horse, so be patient. Unless the horses were completely starved or there is some underlying problem, a feeding program that meets the NRC requirements for adult horses should bring them back to health. If you’re not already doing so, I recommend keeping a journal of their weekly body condition score and results of weight taping.

I actually get this question a lot and have a ready answer for you (it’s probably okay to feed glucosamine to horses that are on sugar-restricted diets), but if you’re not comfortable with this, by all means choose a joint product without glucosamine. There are lots of other ingredients in joint supplements that may help your horse, such as chondrotin sulfate, hyaluronic acid, MSM, cetylated fatty acids and herbs like Devil’s Claw, Yucca, Boswellia and others.

Why do I think it’s probably okay to feed glucosamine to horses that are not supposed to have grain, molasses and other feeds high in sugars? Several reasons. First, a recent study in well-controlled human diabetics showed no effects of glucosamine supplementation on long-term blood sugar levels or diabetes management. Second, a new equine joint supplement on the market that contains glucosamine was given at up to five times maintenance levels for 84 days (that’s 36 grams of glucosamine daily). In two different safety studies of this supplement, no adverse effects on blood sugar levels or any clinically significant effects on any biochemical parameters were seen. Finally, the caution that the NASC requires be on all supplements containing glucosamine came from the FDA, who based it off data from a study of injectable glucosamine.

Because your horse has a complicated medical condition, I recommend you speak with your veterinarian before making any changes to his regimen, whether it’s adding a supplement, soaking his hay or changing his grain.

Without knowing why your two healthcare professionals recommended these products to you, it’s hard to make a suggestion, as they’re three very different supplements. I can tell you two things though: 1) why other people might feed them and 2) when it might not be appropriate to feed them.

Soybean meal (SBM)
1) SBM is high in protein and the limiting amino acid Lysine, so it’s often fed to supplement the protein quantity and quality of a ration. Young growing horses, exercising horses and senior horses might benefit the most.

2) Because it is fairly high in potassium (K) though, it should not be fed to horses with Hyperkalemic Periodic Paralysis (HYPP).

Rice bran (RB)
1) RB is high in fat, so it’s often fed to horses that need additional calories but not from sugars or starches. Thin horses, older horses or those with Polysaccharide Storage Myopathy (PSSM) benefit the most.

2) RB that has not been fortified with additional Calcium has an inverted Calcium to Phosphorous ratio. That is, instead of falling between 1.2:1 and 2:1, RB is one part Calcium to 25 parts Phosphorous! Over time, this can lead to a serious metabolic bone disease.

Beet pulp (BP)
1) BP is high in fiber and can be substituted for up to 25 percent of the horse’s hay or forage. It is often soaked and fed to horses that have difficulty chewing or that choke.

2) Unless the molasses has been removed, it may contain too much sugar for horses with Cushing’s Disease, EMS or PSSM.

I hope this brief description of the differences in the three supplements recommended to you helps you decide which is most appropriate for your horse!

My experience in feeding young horses that did not receive adequate nutrition in utero or while nursing is to still follow the NRC guidelines for their age. Unfortunately, if you attempt to make up deficits now, you may cause additional problems like osteochondrosis or other growth disturbances.

The good news for your yearling is that the mare sacrifices herself to provide for her foal. So it’s possible (as long as this wasn’t her second foal in a starved condition) your colt wasn’t actually deprived of nutrients during this critical phase of growth. Have your veterinarian check out the colt thoroughly, review your nutritional program and recommend a wellness program that includes parasite control, vaccinations, hoof care, dental examinations and turnout or controlled exercise. Ask your veterinarian if you can safely add the limiting amino acids Lysine and Threonine to your yearling’s diet to provide the building blocks of muscle and other tissue without unbalancing the ration.

Basically, try to keep your yearling at an ideal (5) or slightly less than ideal (4.5) body condition score on the Henneke BCS chart, which ranges from 0 = emaciated to 9 = obese. You don’t want him to grow too fast or to get overweight, both of which can lead to complications.

Even though I don’t know what these exact feeds are, a change in grain is not usually a cause of a kidney infection. By definition, an infection is invasion and overgrowth by an infecting organism, usually a bacteria or virus. As kidney infections in horses are uncommon, are you sure your horse has one? If you have not already done so, I recommend seeking veterinary attention to diagnose and treat this condition.

In order to answer your question properly, I need to do two things: explain what founder-prone horses are and then explain the theory behind the ingredients in Quiessence and other products that contain the minerals Chromium and Magnesium.

For years, veterinarians and horse owners have known that one group of horses at risk for developing laminitis are those with Cushing’s Disease. The classic sign of Cushing’s Disease is a long, curly hair coat (hirsutism), but some horses with this condition also have a cresty neck and fat deposits in other parts of the body. Another condition in horses that causes a cresty neck and fat deposits is Equine Metabolic Syndrome, or EMS, previously thought to be due to low thyroid hormone (hypothyroidism). The criteria for EMS is obesity or abnormal fat deposits, insulin resistance and laminitis. So here’s a second group of horses at-risk for developing founder: those with faulty insulin/glucose metabolism.

This is where Chromium and Magnesium come in, two of the ingredients in Quiessence and similar products. Both are known to play a role in the metabolism of insulin and glucose. That is, they are necessary for insulin to act on cells and allow glucose to be taken up and used by the cells. Here’s a very scientific description of exactly how they work:

Chromium—a component of the molecule Glucose Tolerance Factor (GTF), which enhances the action of insulin.

Magnesium—a cofactor of many enzymes involved in glucose metabolism and required for both proper glucose utilization and insulin signaling.

Almost ten years ago the well-known veterinary nutritionist Dr. Eleanor Kellon did a field trial where she gave Magnesium to horses that we would now recognize as having Equine Metabolic Syndrome. In her study, the horses improved in terms of foot comfort, obesity and abnormal fat deposits. Human diabetic patients are deficient in Magnesium and Dr. Kellon believes horses with EMS may be too and that is why they respond to supplementation. A deficiency in Chromium is also associated with diabetes in humans. Most of the studies of Chromium in horses have been to determine if it can enhance performance, but a few have shown improvement in how the body handles glucose after supplementation.

If you’re thinking about supplementing with these ingredients and others thought to support proper metabolic function, get a diagnosis of Equine Metabolic Syndrome first and work with your veterinarian to establish a sound nutritional and exercise program at the same time.

I compared the hoof supplement you’re feeding now with several others on the market and your brand seems to have the most popular ingredients (biotin, methionine, lysine, zinc and copper) in the most common ranges for each. How long have you been feeding this supplement? Horses’ hooves grow anywhere from ¼ to ½ inch per month, so it can take eight months to well over a year to grow a completely new hoof.

There are several other factors that determine the rate and quality of new hoof growth in your horse such as his overall nutrition, the amount and type of exercise he gets, and the day-to-day environment of the hoof (wet, dry). Unless he has other health conditions you didn’t mention, feed two percent of his body weight each day in a high-quality forage and complete his diet with a fortified grain, ration balancer or multi-vitamin/mineral supplement. Make sure fresh water and salt are available at all times. Provide as much turnout as possible (24/7 is ideal) as well as additional exercise such as riding or lunging unless the hoof crack has made him sore. Though it’s best to keep hooves at an ideal moisture—neither too wet nor too dry—going back and forth from wet to dry conditions is worse so do what you can to keep the moisture level in his feet as consistent as possible.

Finally, your question reads like your horse has a vertical crack—maybe a quarter crack? If it’s severe, your veterinarian and farrier may have to work together to stabilize the area. Sometimes this can be done with just a shoe, other times more extensive measures must be used such as inserting metal wires into the sides of the crack and pulling it together. Of course, any infection must be cleared up first and any dead tissue removed to allow healing.

To really give you the best advice, I would need to know things like your filly’s weight and body condition score, also your parasite control program, the kind of environment she lives in (weather, stall vs. turned out, individual or herd) and how long you’ve had her. In lieu of those details, I’ll just provide an overview of “the usual suspects” that lead to thin horses and what to do about them.

Horses can be thin for medical reasons and non-medical reasons. The medical category includes things like parasites, diarrhea, infections, etc. You said your veterinarian checked her out, but I’m curious if he/she performed fecal exams (a regular qualitative fecal exam as well as fecal egg per gram count) since parasites are pretty high on my list of why young horses are thin. At this age, she could still be harboring roundworms (ascarids) in addition to large and small strongyles, so it’s important to make sure she’s being dewormed appropriately. Also, did he/she perform any bloodwork, like a serum chemistry and a complete blood cell count (CBC)? Finally, it would be unusual for a horse this young to have a serious dental problem but a complete physical examination should include an inspection of the mouth and teeth.

Now for non-medical reasons your filly may be thin:

1. Is she getting about two percent of her body weight per day in good quality forage? You may need to weigh your filly and weigh your hay to answer this question. If she’s on pasture, make sure your stocking rate is not too intense and that the pasture is still good quality grass and not mostly weeds.

2. Is she getting the amount of fortified grain that the bag recommends for her age and weight? If you’re feeding less than the bag recommends, she’s not getting enough calories (energy), protein, vitamins and minerals and you need to either feed more or supplement these nutrients with another product.

3. Is she burning calories staying warm where you live or fighting for food and space in a herd? If so, she may need to be kept differently so she’s not using up valuable nutrition meeting her basic energy needs or fending off competition.

4. A yearling is a horse that is still growing so make sure you’re feeding her like a young horse and not an adult horse. Yearlings need increased amounts of energy, protein (amino acids), calcium (in the proper ratio with phosphorus) and other vitamins and minerals. However, simply giving her more “vitamins” without taking into account what she needs and what she’s already getting isn’t the way to go about it and may cause excesses and imbalances leading to serious conditions.

One last note: she’s a breed that is generally considered an “easy keeper,” so you may want to be careful giving her too much traditional grain, especially when she’s young, as some believe this sets horses up for Equine Metabolic Syndrome and insulin resistance. Instead, experiment with putting weight on her by supplementing with the limiting amino acids lysine and threonine, adding fat to the diet, and seeing if pre- and probiotics improve her ability to digest feed.

Just so that everyone’s clear, let me quickly explain what’s going on here, then move on to your question. It sounds like this horse has what is known as “upward fixation of the patella.” The patella is the small, bony plate (the kneecap) that protects the knee joint in people, where the femur and tibia meet. In horses, this joint is known as the stifle. A unique hooking of the patellar ligaments over a notch on the femur allows the horse to lock its hind legs in the standing position. Unfortunately, if one of these ligaments remains in the hooked position, the horse is unable to bend its hind legs. Of the three ligaments that support the patella, it is generally the medial, or inside, patellar ligament that is longer and weaker or “loose.” This problem can range from a slight delay in a leg’s forward motion to completely locking that freezes a leg for long periods of time and may be easier to see when a horse first moves off, is turned, or walks downhill.

Experts aren’t sure what causes this condition, but here are some things that have been suggested:

· Poor muscle condition
· Excessively straight hind limb conformation
· Trauma to the stifle
· Debilitation (undernourishment or ill health)

Upward fixation of the patella is more common in young horses and ponies, and is also seen when a horse is taken abruptly out of training and confined to a stall, losing weight and muscle condition.

Now to your question: did he grow out of it or did the Equinyl Combo help? Personally, I think a combination of things have improved your horse’s condition. First, he is getting older, and as he gains height and weight the problem may be self-correcting.

Two, you added a supplement with ingredients to help manage pain and inflammation, which have been associated with this condition.

Third, and this may be the most important thing, you have begun exercising him daily and providing more pasture turnout. There are some things that may lead to upward fixation of the patella that you can’t change (like conformation), but there are other things that you can change (like muscle tone), and it sounds like you’re doing a great job with that.

I encourage you to continue the exercise and turnout, explore corrective trimming and shoeing with your farrier, and keep him in the best overall health possible by working with your veterinarian to develop a good vaccination, deworming and dental care schedule. Feed him to be at an ideal body condition score (5 on a scale of 1 to 9). If you feel that the Equinyl Combo is helping, by all means continue it. I don’t believe it’s doing any harm and might encourage him to keep moving through some mild stiffness and soreness.

Let me explain to everyone what a pedunculated lipoma is, then comment on your mare’s specific nutrition and supplements. Although on the whole, your program sounds excellent!

A lipoma is a benign fatty tumor. A pedunculated lipoma is a fatty tumor on a stalk hanging in the middle of the abdomen. It can cause intermittent episodes of colic by obstructing the small intestine or severe colic by wrapping tightly around a loop of intestine, shutting off blood supply as well as stopping the flow of food material. This second scenario is a serious form of colic that can only be corrected through surgery. It certainly sounds like the veterinary teaching hospital you’re working with is on the right track with their diagnosis.

Horses most at risk for pedunculated lipomas are older horses (average age is 16 years), geldings and ponies. In addition, obesity is considered a risk factor as the fatty tumor starts as localized plaques of fat that coalesce, or enlarge and grow together.

While there’s nothing at this point you can do to shrink the fatty tumor or prevent it from one day possibly strangulating a portion of bowel, you have already taken steps to reduce her risk of impacting. That is, you have begun to switch from long-stem forage to a more digestible complete feed for older horses. And, you are making this into a slurry that should be even easier to get past a narrowed section of intestine. Ask your veterinarian if you should take her totally off hay and only give the complete feed. If you do, you’ll have to feed the recommended amount on the bag--around 15 pounds per day--since this is all the nutrition she’ll be getting.

A probiotic is a good idea, and there’s no reason she can’t continue to receive a joint supplement. Providing salt is a good way to make sure she drinks plenty and stays hydrated, another way to prevent an impaction. The Red Cell is for her anemia, I assume. Once she goes on the full amount of complete feed, she may not need the multi-vitamin/mineral supplement any longer, however. You have a sensible parasite control program, as additional inflammation or scarring in the intestinal tract is the last thing your mare needs right now. In fact, you may want to talk to your veterinarian about putting her on a daily dewormer.

It sounds to me like you’re doing everything you can to help your mare stay happy and comfortable as long as possible. She’s lucky to have such a conscientious owner!

This is a tough one, as there’s no scientific research to support the use of garlic and other products (apple cider vinegar, diatomaceous earth) to repel insects, yet many people swear by these natural products and continue to use them year after year. The fact that there’s no supporting research doesn’t mean the products don’t work, it just means that because they’re natural products that can’t be patented, no company is going to spend hundreds of thousands of dollars proving they work only to have 20 other companies profit from their study.

There was a research paper published in 2005, evaluating the safety of garlic in horses because very high doses of the herb are known to cause a specific kind of red blood cell disorder. The research showed that horses that would voluntarily eat more than 0.25 grams of freeze-dried garlic per kilogram of their body weight, twice daily, did develop Heinz body anemia. To put this into perspective, an 1100 pound horse would have to eat 4.4 ounces of pure garlic in two separate meals. Now, this is much more garlic than the label of any equine supplement recommends be fed, but it does show that just because something is natural doesn’t necessarily mean it is safe.

First of all, it’s hard to make nutrition and supplement recommendations without knowing a little bit more about your horses and what you do with them. For example, if you were to tell me you have young Thoroughbreds that you compete at the advanced level of three-day eventing, I would give you much different advice than if you were to tell me you have 20-year-old retired Quarter horses that don’t even get ridden anymore. So without knowing more, I can only comment on what your nutrition choices: pasture, a handful of grain and the three supplements you’re giving them.

I assume the pasture is of high-quality and can provide adequate nutrition throughout the year since you only give hay at certain times. I’m also going to assume the very small amount of grain you’re giving them is just as a carrier for their supplements since it’s not enough to provide an adequate amount of vitamins, minerals, protein or calories. Now for your supplements.

It looks to me like you have some redundancy in the products you have selected. Both Missing Link Plus and Sho-Glo are designed to complete and balance a forage-based diet, so you only need one of them. The biggest differences are Missing Link Plus contains Glucosamine for joint support as well as Omega-3 Fatty Acids while Sho-Glo contains a much more comprehensive vitamin/mineral package as well as yeast culture. While Nu-Foot sounds like a hoof supplement, it too contains quite a few vitamins and minerals, not just the usual Biotin, Methionine and Zinc found in most hoof supplements. So you may want to consider switching to a less “potent” product for healthy feet, as this one is advertised as an anti-fungus supplement that is also good for healthy normal skeletal growth in young horses.

I’m not aware of probiotics or mineral supplements being used to help reduce the feeling of hunger in horses. However, if you’re not feeding the amount of lite feed recommended on the bag, your horse may be deficient in vitamins and minerals, which many believe cause horses to eat manure, chew wood or lick dirt. Some new, low-calorie feeds have recently been introduced to the market, which provide these vitamins and minerals in a full-feed formula so your horse feels full but doesn’t take in as many calories as he would with a traditional fortified grain. Other ways to make sure your horse gets all the vitamins and minerals he requires without excess calories is to feed a ration balancer or a multi-vitamin/mineral supplement.

Here’s some additional advice for your easy keeper:

· Feed more mature, stemmier hay, which has more indigestible fiber and less sugars and starches
· Limit access to grass—turnout onto a dry lot, use a muzzle or only graze during early morning hours
· Provide at least 30 minutes of exercise a day

There has been some research to show that certain probiotics—such as the yeast Saccharomyces cereviseae—can help reduce the risk of digestive disorders such as colic when fed to horses on less digestible diets. For this reason, you may want to supplement with a product that contains this micro-organism, but not necessarily to help with his hunger.

It sounds like you’ve really done your homework! I congratulate you for putting such thought into your horses’ nutrition while they’re young like this. You’re doing a good job of setting them up for a long and healthy partnership with you!

Sometimes people make nutrition more complicated than it is, but you seem to have an excellent grasp on what your horses’ need. The short answer to your question is: weigh the product you’re feeding and give it according to the directions on the bag. Your “forage enhancer”, which is also known as a “ration balancer” is designed to complete and balance the diet of horses being fed just pasture or hay. It contains vitamins, minerals (and protein) in amounts and ratios that should complement grass-based forage specifically.

If you know that your pasture or hay has adequate protein, you could get by with just providing a multi-vitamin/mineral supplement. As the name implies, these products contain only vitamins and minerals—not protein—and are fed in 1 and 2 ounce amounts instead of 1 and 2 pounds. Some even come in pelleted form so you still don’t have to feed any grain to mix them in.

During the summer when your horses on are pasture, you might even be able to move down another rung on the ladder by feeding just a mineral supplement. Fresh grass should have adequate amounts of the vitamins that degrade in the cutting, drying and curing process of making hay.

Live bacterial cultures are also known as direct fed micro-organisms or probiotics. They’re the “good bugs” and have names like Lactobacillus, Enterococcus, Bifidobacterium and Bacillus. Aspergillus, a fungus, and Saccharomyces, a yeast, are also considered probiotics. Nutritionists define them as “live micro-organisms, which when administered in adequate amounts confer a health benefit on the host.” Some of these health benefits include: making B vitamins, producing energy, suppressing “bad bugs,” and supporting the immune system. That is, they help maintain a healthy digestive tract and help the host extract the most nutrition possible out of the diet.

Although probiotics are used quite frequently in horses (and humans and pets), we are just now beginning to see good scientific research to support their use. For example, the yeast Saccharomyces has been shown to increase the digestibility of fiber in the diet, improving milk quality in mares and enhancing growth in young horses. By digesting the higher levels of cellulose and hemicellulose in poor-quality hay, Saccharomyces may play a role in preventing digestive disorders associated with hay that is too coarse for the horse to digest itself. Supplementing with Saccharomyces has also been shown to allow some horses to better tolerate high sugar/starch diets without developing digestive disorders such as colic or hind-gut acidosis (too-low pH values in the cecum and colon).

Fortunately for you, there has been quite a bit of research conducted recently on tying-up, also known as Exertional Rhabdomyolosis (ER). Dr. Stephanie Valberg’s group at the University of Minnesota College of Veterinary Medicine Neuromuscular Diagnostic Laboratory www.cvm.umn.edu/umec/lab/home/html has done a great job defining this condition and separating it into three forms:

1. Sporadic ER—horses of any age, breed, gender or discipline that experience occasional episodes of tying-up due to some temporary muscle imbalance.
2. Recurrent ER—Thoroughbreds, Standardbreds and Arabians with an inherited defect in muscle cells that causes tying-up on a chronic basis.
3. Polysaccharide Storage Myopathy (PSSM)—Quarter horses, draft horses and warmbloods with a different genetic disorder that causes a slightly different version of tying-up.

It sounds like your horse has the second type, Recurrent ER. The classic case is a young, nervous, Thoroughbred filly just starting race training in which episodes of tying-up (muscle stiffness and pain) are triggered by exercise and excitement. I’ll assume your veterinarian has correctly diagnosed the condition and that together you appropriately manage each episode as it happens so I’ll skip right to your question: what to feed her.

The key is decreasing starches and sugars (non-structural carbohydrates or NSC) and increasing fat. Recommendations are to provide no more than 20 percent of the horse’s total daily calories through NSC because these simple carbs are a source of quick energy that can make some horses excitable. At the same time, up to 20 percent of the horse’s total daily calories can be provided through fat as a source of calm energy and calories to maintain body condition. Practically speaking, you want to feed as little grain as possible, and gradually introduce fat to the diet through rice bran, vegetable oils or powdered fat.

Experts suggest that whenever adding fat to the diet, Vitamin E should also be added as an antioxidant. To be on the safe side, you should investigate how much Selenium is in your hay and grass (and grain) and decide if that should be supplemented too. Feeding electrolytes to a horse that ties-up is never a bad idea. Also, Chromium and Magnesium, two minerals, have been suggested to calm horses and improve their responses to exercise, which may be beneficial to horses with Recurrent Exertional Rhabdomyolysis.

I’m sorry to hear that your horse had colic. I assume it was the first time for him? Without some details (age, breed, use, living arrangements) it’s hard to give specific advice, but I would like to share with you an important study on colic, performed right there in your own home state.

Dr. Noah Cohen, along with Pete Gibbs and April Woods, found the following factors to be significantly associated with an increased risk of colic:

· Recent change in diet
· Recent change in type of hay
· History of previous colic
· Recent change in weather conditions
· Recent change in stabling
· Arabian breed
· A deworming within 7 days of the episode
· Failure to receive regular deworming
· Age > 10 years
· Regular exercise (vs. pastured at all times)

Getting back to the hay, coastal hay is generally considered of poorer quality than some other grass hays, making it less digestible. According to another study, feeding coastal hay is a clear-cut risk factor for small intestine impaction colic. I know that’s not the kind of colic your veterinarian said your horse had, but it might be a good idea to (gradually!) switch to another kind of grass hay or improve the quality of your coastal hay, if possible. Substituting other forms of forage such as beet pulp or hay cubes for a portion of the coastal hay you’re feeding is another idea. Finally, you could add pre- and probiotics and digestive enzymes to your horse’s diet, since some (such as the yeast Saccharomyces cerevisiae) have specifically been shown to improve the digestibility of forage.

Electrolytes in Texas is never a bad idea, and they may stimulate your horse to drink more, keeping him well hydrated. Wetting the hay may also provide him with additional water. However, I can’t think of a reason why adding oil to a diet would help with colic, but it shouldn’t hurt, and it will make him nice and shiny!