Ask The Vet: Supplements - March 08

I put your two questions together because they both basically ask if you should be supplementing your horses with Osteo-Form Powder by Vet-A-Mix, a division of Lloyd, Inc. Here is that company’s response:

Developmental Orthopedic Disease (DOD) is considered to be a multi-factorial syndrome comprised of genetic, management and nutritional components. All three aspects should be addressed when investigating any type of DOD problem. Rather than add a supplement that may be unnecessary or perhaps detrimental, a comprehensive examination of all three factors are warranted. For a more thorough description of this type of comprehensive examination, see “Appendix A, Applied Nutrition” in Equine Internal Medicine, Second Edition; Reed, Bayly, and Sellon, Eds.; Saunder, 2004).

In brief, investigating growth-related problems on a farm should include: the measurement of some basic physical parameters of all mares and foals on the farm (height, weight, body condition score); blood chemistry analysis of affected foals, normal foals, and the mares; record of how many hours per day the mares were on pasture with access to fresh grass; an accurate chemical analysis of all feeds, supplements and water that are fed to the mares and foals; an accurate determination of feed consumption by each mare and each foal; record of which supplements are offered free-choice and which animals had access to them; record of how long the pregnant mares and growing foals had access to the current feeding program; examine the pedigree of all mares and sires to look for similarities in affected foals.

As you can see, it is not a simple matter to pinpoint a potential cause of DOD-related growth problems on a farm. However, with an adequate diet, additional supplements may not be indicated and may even be detrimental. For example, the calcium-phosphorous (Ca-P) ratio is very important to maintain within a small range of normal limits, and in a diet that is deficient in phosphorus, supplementation with additional calcium can actually bind to the little phosphorus that is present in the gut and inhibit absorption, thereby exacerbating the phosphorus deficiency!

In answer to Question #1: Because the blood analysis on the affected foals shows no calcium or phosphorus abnormalities, I would not recommend any supplementation without first analyzing the Bermuda grass hay and alfalfa for calcium and phosphorus to determine if the feed has any deficiency that would suggest supplementation would be helpful.

For Question #2: Again, I would not suggest any supplementation without a more thorough comprehensive examination of the farm as described in the second paragraph above, including feed analysis, blood chemistry analysis and feed consumption by individual animals. Some animals may require supplementation whereas others may not. While some alfalfa is very phosphorus-deficient, it could be dangerous to supplement without knowing whether the alfalfa being fed to these particular horses is, in fact, phosphorus-deficient. Is it best to know exactly what deficiencies are present before trying to correct any perceived deficiencies in the diet.

Insulin resistance (combined with laminitis and obesity) make up what is now being called Equine Metabolic Syndrome (EMS). Reducing the obesity is paramount to success and a three-pronged approach is necessary to achieve this. First, reduce the sugars and starches in the horse’s diet by replacing grain with a vitamin/mineral supplement, ration balancer or low-starch grain and remove the horse from pasture while making sure the hay is less than about 10 to 15 percent sugar/starch. Second, provide exercise! While turnout is nice, usually these “easy keepers” will not exercise themselves, so you have to handwalk, lunge, ride, drive, pony, etc. Daily is best, twice-daily is even better! Consult with your veterinarian, though, about forcing exercise on your laminitic horse, and remember to start any exercise program slowly. The third step is supplementation.

Experts studying EMS suggest that enhancing the whole-body antioxidant status might be beneficial in the management of metabolic syndrome. Dietary supplementation with high levels of vitamin E has been associated with clinical improvement in equine patients affected with motor neuron disease, another condition associated with depleted whole-body antioxidants, and might be logically and safely used in the management of obese horses. A growing body of research supports the use of antioxidants such as vitamin E, grape seed extract, alpha lipoic acid and other compounds in the management of equine metabolic syndrome.

Several products have been formulated in the spirit of supporting and maintaining healthy metabolic function and SmartControl IR is one of them. These products generally contain antioxidants, certain herbs, amino acids, vitamins and minerals that are believed to support healthy blood glucose and insulin levels. While Quiessence was originally developed as a calming supplement, the chromium and magnesium it contains have made it a popular choice among veterinarians and horse owners to help regulate insulin and glucose in the body.

Below is a list of some of the active ingredients in SmartControl IR, along with their understood impact on the healthy structure and function of metabolic pathways:

Banaba Leaf Extract – may increase insulin sensitivity and improve hyperglycemia

Biotin – may enhance insulin sensitivity and glucokinase activity in the liver

Bitter melon – may help stimulate insulin release and possibly glycogen synthesis in the liver

Chromium – a component of glucose tolerance factor (GTF) which potentiates the action of insulin

Cinnamon – may increase glucose disposal by enhancing translocation of glucose transporter 4 (GLUT-4)

Fenugreek – may have hypoglycemic properties

Magnesium – cofactor of many enzymes involved in glucose metabolisms and is required for both proper glucose utilization and insulin signaling

Taurine – amino acid that may act as a minor insulin mimetic

It is important to note that SmartControl IR and other supplements in this category do not treat or cure the underlying disease, but may be helpful in managing the associated oxidative stress and in supporting proper, healthy metabolic function. In fact, the product is currently the focus of a research study by Dr. Nick Frank at the University of Tennessee. By the end of April 2008, we should have data on exactly what kinds of effects it has on body weight, regional fat deposits (such as a cresty neck) and insulin and glucose levels.

If you had asked me should your 19-year-old horse that is perfectly sound be started on a joint supplement, I could have gone either way. While many people choose to put their horse on a joint supplement once they become seniors (if they weren’t already on one), many people don’t, and that’s fine. However, because it sounds like your horse is recovering from a fairly serious issue involving more than one joint, and is currently showing clinical signs of arthritis, I have to recommend that you keep her on an oral joint product. Work with your veterinarian to customize a joint care regimen specifically for her. This may include more turnout and less stall-time; more or less exercise; prescription products given directly into the joint, into the muscle or into the vein; an over-the-counter oral joint supplement; and anti-inflammatories as needed. I wish the two of you many years of trail riding!

First, let me say that I love the fact that your horse has 15 hours per day of turnout, and that you’ve done your homework when it comes to researching his issues. Now, look through the other "Ask A Vet" questions for the one about a 4-year-old gelding that cribs. In my response, I share potential causes of cribbing as well as possible management strategies from the latest Nutrient Requirements for Horses.

Now for your feeding program. Let’s see, you’re feeding grass hay (probably 10 pounds?), 5 pounds of alfalfa pellets, two kinds of fat, and Equilizer (Equalizer?). Purina does not offer this product in the United States, so I’m assuming you’re not from this country? If it’s a vitamin/mineral supplement or a ration balancer specifically designed to be fed with a primarily grass hay diet, then it sounds like your horse is probably getting everything he needs. My only advice is to add Vitamin E as an antioxidant for the fat.

For more information on what hoof supplements have been proven to do, please visit my other posts—hoof problems and the benefits of supplementation were popular questions this month! The bottom line is that horses with certain hoof conditions--such as poor hoof horn quality; brittle and chipped hooves; and weak, misshapen and crumbly hooves--did show improvement after long-term biotin use.

However, a vertical crack is a different situation. While you should definitely do everything in your power to encourage healthy, rapid growth of hoof horn, it will take more than a supplement to improve your particular horse’s feet and prevent this from happening in the future.

Your farrier/veterinarian team will need to work together to come up with an appropriate solution for your guy. This will most likely involve immobilizing the crack, which can be done in a variety of ways. I recommend you go to Dr. Stephen O’Grady’s website for more information on all things hoof-related: www.equipodiatry.com

Since hay contains very little fat, when you say there are omega-3s already in your horse’s feed, you must mean in his fortified grain. And, I assume the brand of grain you are feeding specifically says omega-3 on the label, because that is not required to be listed. Generally, cereal grains are higher in the omega-6 fatty acids, which is why some horse owners are interested in giving their horses omega-3 to restore the balance or ratio between the two. Horses (and all animals) need both kinds for their bodies to function well.

The current theory is that omega-3 fatty acids are anti-inflammatory and omega-6 fatty acids are pro-inflammatory. This downgrading of the body’s natural immune response is probably where you got the idea that omega-3s “negatively affect their immune system.” For horses with conditions like allergic skin disease, autoimmune disease, recurrent airway obstruction (heaves) and others, that’s exactly what horse owners are hoping the omega-3s will do! For other conditions, like fertility issues in stallions, EIPH and laminitis, the ability of omega-3s to alter cell membranes and red blood cells may be how they exert their beneficial effects.

If your horse’s primary source of forage is fresh green grass, then he may already be getting enough omega-3s to produce a shiny coat, healthy hooves and even support his joints. But, if he mainly eats hay for roughage, then here are some guidelines.

A study by O’Connor and others entitled “Dietary fish oil supplementation affects serum fatty acid concentrations in horses” showed that 63 days of supplementing fish oil at the rate of 324mg/kg of body weight was enough to alter the fatty acid profile and blood lipid properties of horses receiving regular exercise. To put this into practical terms:

324mg/kg body weight X 500kg horse = 162 grams (or about 7 ounces) of fish oil

Fish oil is 10.8% EPA and 8% DHA, so the amount above would provide 17.5 grams EPA and 13 grams DHA.

Besides fish oil, other good sources of omega-3s include ground stabilized flax seed and linseed oil, as well as canola oil. Other studies have provided 8% by weight of ration in linseed oil and 454g flax seed per 450kg body weight.

There are many reasons why young horses might become unpredictable and stronger with a new owner, in a new situation and when introduced to new horses, but that’s a different Ask A Vet! I will focus on what you should and should not feed him to improve his behavior.

I’m curious what he was fed before you bought him, and why you are feeding him the things you are: cubes, chaff and sugar beet. These aren’t typical US horse feedstuffs; are you in a different country? The basis for a horse’s diet in this country is usually long-stem forage like hay or grass, a fortified grain or vitamin/mineral supplement to meet nutrient requirements and a source of calories to meet energy needs. I’m afraid I’m not familiar enough with the components of your horse’s diet to know if it’s complete and balanced and if it might be the source of his undesirable behavior.

There’s quite a bit of research on feeding fat to horses not only to put weight on them (which you are looking for), but also to provide a concentrated source of calories that will not make them “hot,” as cereal grains are thought to do. In Thoroughbred racehorses that tie up, reducing sugar/starch and increasing fat causes horses to be less nervous, a trigger factor for tying up.

I recommend working with your veterinarian or local nutritionist wherever you are to first, make sure your horse is on a complete and balanced diet, and second, determine if and how much fat might be appropriate to help him gain weight yet stay cool and calm.

I’m not sure whether to sympathize with you or congratulate you for dealing with all these issues in your horse! Obviously, you work closely with your veterinarian to not only maintain your horse, but also continue to compete him. I’m not sure that I can or should recommend anything else than what you’re already doing, because if it ain’t broke, we don’t want to fix it!

Regardless, I do have a couple of ideas, but I strongly encourage you to run them by your veterinarian first before implementing them, because they may interfere either with your horse’s pre-existing conditions or your current management of those conditions. By the way, what led you and your veterinarian to test for Cushing’s when your horse was not showing any signs? Sometimes the diagnostic testing, especially the ACTH test, can be falsely positive. I encourage you to have him retested with the low-dose dexamethasone suppression test, just to make sure he really does have Cushing’s disease.

Here are my ideas:

Plant adaptogens – to help your horse’s metabolism return to homeostasis

Omega-3 fatty acids – to reduce inflammation in your horse (specifically his allergies and his uveitis)

MSM – another anti-inflammatory, unless this is already in your joint supplement

Pre- and Probiotics – to assist your horse’s aging GI system in extracting nutrients

Vitamin C and the B Vitamins – older horses make less of these, just when they need them more

Vitamin E and other antioxidants – to combat the oxidative stress associated with diseases like Cushing’s

When starting new supplements (especially for a horse with allergies like yours), I always recommending adding one at a time and watching your horse closely for any changes.

I commend you for thinking ahead to the long-term welfare of what sounds like three incredible young horses! While no research has proven that oral joint supplements can prevent osteoarthritis, studies have shown that glucosamine, chondroitin sulfate, hyaluronic acid and other common joint supplement ingredients may stimulate cartilage synthesis and inhibit cartilage breakdown.

One way to look at oral joint supplements is as an “insurance policy” for your horses’ lasting soundness. Arthritis develops because of wear and tear of joints over years of relatively moderate work. Of course, trauma, poor conformation and other issues can increase the rate at which the tissues in your horses’ joints break down. As a concerned horse owner, why not “stack the deck” in your horses’ favor by providing the building blocks of healthy joint tissue so that when they need these ingredients to repair cartilage, synovial fluid and other joint components, they are already on board.

I can answer this one fairly quickly: biotin for her feet and fat for her weight! All kidding aside, obviously there is more to both of your mare’s issues than this, but I’ve covered feeding the hard keeper (and supplementing for poor hooves) pretty extensively in other posts, which you should read. I go into what quality is your hay, have you weighed how much you are giving her, can you provide grass hay 24/7, can you add in some alfalfa hay, does she have access to fresh grass, etc. As far as grain, I question why you feed rolled barley (not really a common horse feed anymore). Is your mare receiving at least her minimum daily requirements between the cereal grain and her two supplements? How many meals a day are you providing? Is she having to compete for her food? What is her complete amino acid profile, and so on?

Between her hay, grain and her genes, is she truly getting enough calories to put on weight as well as be exercised? Fat has proven to be an excellent source of concentrated calories for horses. It helps many horses gain weight as well as have energy for exercise without making them “hot” like cereal grains can. Just be sure and start slow so her GI system adapts to digesting and absorbing the fat and her muscles adapt to using the fat first for energy, rather than carbohydrates or protein. Your choices for fat include commercial fortified grains with added fat, commercial fat supplements for horses, flax seed and other natural products, rice bran and vegetable oils.

Without seeing your horse’s behavior first-hand, and performing a complete physical examination on him, it’s hard to have any better theories than your veterinarian about what might be going on here. However, it should be possible, with a bit more diagnostic testing, to determine if his behavior is caused by a dermatological (skin) problem or he has a stereotypy (self-mutilation). I recommend you ask your veterinarian to refer you to a veterinary teaching hospital or the nearest equine referral clinic in your area, and have your gelding thoroughly investigated by both a board-certified dermatologist and a board-certified behaviorist. If a behaviorist isn’t available locally, many of them will allow you to send in a video tape of your horse’s abnormal behavior, then consult with you, and your veterinarian long distance.

In the meantime, here are a couple of articles for you to read about each possible cause:

Equine self mutilation syndrome:
www.ivis.org/proceedings/aaep/2005/mcdonnell/chapter.asp?LA=1

Dermatologic conditions:
www.ivis.org/proceedings/aaep/2006/white8/chapter2.asp

You don’t mention what body condition score your horse is, but I assume he must be near ideal or you would have told me he needed to either gain or lose weight. Although he’s getting close to the amount of complete feed recommended by one of the manufacturers (12.4lbs with no hay, decreased by one pound for every 2 to 3 pounds of hay fed), I’m not a big fan of mixing commercial feeds. I believe that each manufacturer develops a product and recommends a certain amount be fed because they assume you will only be feeding their product. So, rather than getting the best of both worlds, you might be getting less than the best from each.

If your horse is having trouble chewing long-stem hay to the point of quidding (dropping food out of his mouth), be careful that he doesn’t choke. You may want to feed chopped hay, hay cubes (soaked) or hay pellets so he still has forage, but it’s in a more available and safer form.

I see that you’re giving him two sources of fat. Although you don’t say which version of Ultimate Finish you’re using or how much, between it and the corn oil, you may want to provide him with additional Vitamin E as an antioxidant to scavenge the free radicals created when the body metabolizes the fat for energy. Are you feeding the fat for additional calories and energy?

My only other advice is to watch him carefully for development of insulin resistance, which can occur in some horses that have Cushing’s. I recommend regular follow-up visits from your veterinarian that includes bloodwork to monitor progress of his disease(s).

There are a couple of other questions this month about selenium that I encourage you to read. In general, I’ve found that horses require at least 1mg of selenium per day, that 3mg has proven benefits such as improved immunity and that 5mg is approaching the upper end of the safe window. Your job is to figure out between his grass, hay and grain how much selenium he is currently getting per day and then, which of the available multi-vitamin/mineral supplements contains the most appropriate level of selenium to complement what he’s already getting. Your veterinarian should be able to help you with this.

I don’t know which vitamin/mineral supplement you’re giving, but I looked through several brands that we sell and couldn’t find any that recommended feeding twice a day. Most said to feed a certain amount (1 ounce, 1 scoop, etc.) per head per day or just “daily.” So, although I usually encourage people to follow the recommendations on the manufacturer’s bag (they are there for a reason!), in this case I don’t see any harm in feeding the entire amount at one time. Unless there are other ingredients besides vitamins and minerals in the product you’re using, your horse should get the full benefit of the supplement even if it’s just given once daily.

Hmm, this is a tricky one. With her history of liver disease, I can see why fat supplements might not work. I can also see that my next recommendation, high quality protein, might not be appropriate, because metabolizing that protein may put additional stress on her liver.

Let me ask you some questions. You say you are feeding her a complete feed. Is there a reason she can’t have hay? While alfalfa hay, with its high protein content, might not be the best choice, unless her teeth are bad, I would keep high-quality grass hay in front of her all the time. If you can turn this mare out on pasture, even better! Then you can feed her a true concentrate, or fortified grain, that has vitamins and minerals along with calories in the form of your preferred grain, be it corn, oats, barley, etc. While it seems like the whole world is on an anti-grain kick now, trying to keep sugar and starch as low as possible, these energy sources might be the wisest choices in your mare, as they are much easier to digest, absorb and use than fat and protein, given her preexisting condition. Just make sure not to give more than about five pounds of grain per feeding. In fact, when I’m trying to put weight on horses, I feed them as many small meals per day as I practically can. She should be separated for all her meals, so there’s no competition, but remain in sight of other horses so there’s no stress.

As far as supplements go, you could try one of the products designed to protect the hindgut from acidosis and ensure proper fiber digestion. Since fermentation of fiber in the large intestine is a major source of energy for the horse, this might really help your mare. Products in this category include Yea-Sacc, EquiShure and Succeed, among others.

Pro- and pre-biotics are another supplement choice. Probiotics are the actual “good bugs” that live in the hindgut and digest fiber. They also produce many of the B-vitamins that the horse uses. Prebiotics are food for these good bugs, keeping them alive and healthy even if the horse’s diet changes and their usual and preferred food source is no longer available.

Finally, if appetite is an issue, try a product with fenugreek in it, an herb recently ranked first in a study of flavor preferences of horses! The same author also did a study where horses ate more forage (both grass and hay) when they were provided some variety, instead of just one kind day after day. I hope some of these product and management suggestions help you two!

Unless you are working closely with an equine nutritionist or have extensive nutrition training yourself, I cannot recommend that you mix your own feed for your horse. Commercial feed manufacturers are experts at obtaining quality ingredients and formulating rations for the various lifestages and lifestyles of horses and have research to back up their products.

Instead, I would back up a step and try to figure out what is actually causing your horse’s allergies. This way, you might be able to change one or two things about his feeding or management program—or desensitize him to one or two things—and reduce his threshold for reacting.

Ask your veterinarian to refer you to a board-certified dermatologist for a complete physical examination, exhaustive history of his problems (I hope you’ve been keeping a detailed journal!) and specialized allergy testing. I think you will have better luck with this approach rather than trying to create your own diet for him. The dermatologist will work with you to remove every possible allergenic substance he is exposed to, and then add them back in one at a time and watch for reactions. You will be advised to put him on a very specific diet for a short time to see if that improves his condition. You will probably also be instructed to change his bedding, remove him from pasture if he gets any, and stop all topical products, such as shampoos and fly sprays. Obviously, insects (especially in your neck of the woods) are a major cause of allergies in horses, so this aspect will be investigated too.

It’s a long and tedious process, but if you’ve been struggling with allergies for the entire six years you’ve had your horse, diagnosing the problem with the help of a skin expert might be in your and your horse’s best interest. Once you’ve got a handle on things, I recommend (with the veterinary specialist’s approval), supplementing with omega-3 fatty acids, as they have been shown to decrease inflammatory mediators and even the allergic skin response in horses suffering from recurrent seasonal “itchiness” due to Culicoides (sweet itch).

Unfortunately, I have not been able to find any sort of guidelines for which supplements or ingredients should not be mixed together for a length of time before feeding. After speaking with several research scientists and nutritionists however, I did learn that it’s a complicated issue and it’s probably best NOT to mix supplements.

For example, products containing unstabilized fats should not be combined with products containing antioxidants like Vitamin E, Vitamin C or Vitamin A because the fats rapidly degrade the antioxidants, essentially using them as preservatives. Then they are not present in the amounts listed on the label anymore and the horse doesn’t get them as vitamins or antioxidants or whatever their intended use. Some inorganic minerals can have similar chemical reactions with certain other ingredients and reduce them to meaningless levels.

What I learned from this brief foray into the biochemistry of nutrition is that the specific ingredient and the chemical form it’s in have a lot to do with whether it will react with other nutrients. Therefore, it’s probably best to trust manufacturers to know which ingredients can be combined with which other ingredients in their own product, and that combining two or more different products, even from the same manufacturer, is probably not a good thing.

Please read my other posts regarding selenium. As I told another person, the minimum daily requirement for a mature, 1000 pound horse is about 1mg. Benefits have been shown by increasing that amount to 3mg per day, but be careful feeding 5mg or more of selenium daily as that seems to be the amount when signs of toxicity begin to occur.

There are a number of supplements that come to mind when asked a question like this. Changing hay and grain (gradually) and seeing if that prevents these bouts of colic is also an option. However, I strongly encourage you to try to get to the bottom of your horse’s colic first. That is, work with your veterinarian through a series of questions and diagnostic tests to determine if sand, enteroliths, parasites (eg small strongyle emergence), ulcers, dehydration, change in pasture or feed or other medical or seasonal issue could be the cause.

If you cannot identify a trigger factor, and you feel your horse is getting appropriate forage, vitamins and minerals either in grain or a supplement, water, turnout and preventive care (eg deworming), then you may want to begin experimenting with supplements across several categories to see if any help. I recommend trying one supplement at a time though, rather than several at once, because then you won’t know for sure which supplement helped. During these trials, keep detailed notes about any changes in your horse that you notice.

The first category you may want to start with is a daily dewormer. If inflammation caused by parasite migration is the root of your horse’s intermittent colic, then feeding pyrantal tartrate every day may be of benefit.

The next category of supplementation could be with psyllium. A paper in the Feburary 2008 issue of the Journal of Equine Veterinary Science entitled “Fecal Sand Clearance is Enhanced with a Product Combining Probiotics, Prebiotics and Psyllium in Clinically Normal Horses” suggests such products may be an effective prophylactic treatment for sand enteropathy and sand colic in which management alone is not sufficient to prevent intestinal sand accumulation.

If you would like to try probiotics (the good bugs) and prebiotics (food for the good bugs) alone, there are a variety of products on the market from which to select. Because it has been shown that different strains of probiotics (such as Lactobacillus, Enterococcus, Aspergillus and others) work differently, try to find a product with more than one strain.

There are a couple of products in the digestive category of supplements that have been shown to stabilize colon pH, decreasing the risk of hindgut acidosis, which can lead to colic (and laminitis). Yea-Sacc contains the yeast Saccharomyces cereviseae, while EquiShure contains a time-released hindgut buffer. Another product, Succeed, is described as a complete digestive conditioner for the entire GI tract, and contains polar lipids, beta-glucans, glutamine, threonine, nucleotides and yeast.

Unfortunately, there is no consensus among experts about what constitutes a “senior” horse—some say 15 years, some say 20. Most agree, however, that it is not based on chronological age but on physiological age. That is, the age at which physiological functions like digestive efficiency and immune status begin to decline. Therefore, you and your veterinarian must work together to determine if your mare is aging well (looks and acts like a horse under 10) or aging poorly (looks and acts like a horse over 20). A horse that is “showing its age” may have a poor quality hair coat, reduced activity and muscle loss especially over the topline.

If this describes your horse, then it may be time to gradually switch to a commercial senior feed, which has high-quality, easy-to-digest protein, increased amounts of certain nutrients (like B vitamins and Vitamin C) and reduced amounts of other nutrients like phosphorus. Some owners like to add direct-fed microbials (probiotics) to their senior horse’s diet to help maintain normal intestinal function. Of course, high-quality hay is still an important part of your horse’s ration, as long as she can safely chew it. As horses get into their teens and twenties, I generally recommend increasing the frequency of dental examinations to twice a year instead of just once, to catch problems earlier.

And while a horse her age in her line of work certainly may be experiencing “wear and tear” of her joints, there may be other reasons for her to be stiff and sore in the hind. I recommend you have your veterinarian examine her and provide you with an appropriate diagnosis and treatment plan that may include an oral joint supplement as well as prescription medications and specific management suggestions.

I’m impressed with the fact that you know exactly what and how much your horse is being fed! Based on what you’ve told me, I think you’re doing a good job of meeting all his specific dietary and health needs without overdoing it. He receives a mixed hay for his forage needs, a small amount of grain supplemented with a multi-vitamin/mineral (that also contains amino acids), some additional fat to maintain condition and coat, probiotics to support his aging digestive system and two complementary joint products for arthritis.

The only other things I can think of for you to ask your veterinarian about are additional antioxidants such as Vitamin C and Vitamin E and potentially MSM as an anti-inflammatory to provide even more musculoskeletal support. But, you’re doing a great job—keep it up!

What a wonderful surprise to wake up to one morning! If your mare is in good flesh (around 5 on the Henneke Body Condition Scoring chart, which ranges from 1 = emaciated to 9 = obese), then there probably hasn’t been any harm in not knowing and planning for a foal. However, lactation is more demanding than gestation, so now you do have to make sure your mare is getting enough energy, protein, vitamins and minerals to both maintain her body condition and support a growing horse.

You don’t say what kind of grain you’re giving her, but I assume it’s a commercial, fortified concentrate that specifically mentions mares in her lifestage (pregnant and nursing) on the bag. I also assume you’re feeding at least the amount recommended by the manufacturer for her weight. You may be feeding more than this, which is fine, just make sure you don’t feed more than about five pounds of grain at any one meal.

Between the grain and the alfalfa hay/pellets, she’s probably getting enough protein, but read my answer to the person wanting to know exactly how much protein a pregnant mare should have. I provide the NRC’s recommendations for both gestation and lactation and even play around with math using practical feeding examples, which will also be helpful to you.

Have a conversation with your veterinarian about how and when to creep feed, as this will help take some of the pressure off the mare and ensure that the new addition to your family is meeting his minimum daily requirements of key nutrients. If you’re still concerned that mom or baby may need additional supplementation to meet their nutritional needs, ask your veterinarian if a multi-vitamin/mineral supplement formulated for these purposes might provide safe “insurance.”

To answer your last question first, no, fat supplements are not recommended for all horses. Horses that are overweight or obese (body condition scores of 7, 8 or 9 or “easy keepers”) probably should not have additional fat in their diets. And, any horses that do not seem to be able to digest, absorb or metabolize fat, probably should not be fed any.

What horses DO benefit from fat?

* Horses that need to gain weight (“hard keepers)” who are already on a complete and balanced ration with plenty of forage and moderate levels of grain

* Horses that get “hot” on grain, but need extra calories to maintain weight and

* Condition horses in heavy training or competition that cannot get enough calories from forage and grain alone

* Horses that “tie up” or develop exertional rhabdomyolysis when fed large amounts of grain, like Thoroughbred race horses

* Horses with polysaccharide storage myopathy or PSSM, whose muscles do better metabolizing fat for energy rather than sugars or starches

In addition, we are just beginning to recognize the benefits of the anti-inflammatory omega-3 fatty acids in supporting healthy skin, coat and hooves; fertility; joint health and other organ systems. Fortunately, you do not have to feed large amounts of omega-3 fatty acids to make a difference, just be sure that the fat source you are using definitely contains omega-3s. If you’re going to add fat to the horse’s diet, you should probably add Vitamin E as an antioxidant.

Remember that a horse’s topline, and in fact his entire body, is a combination of fat AND muscle, and that we should feed to both meet (or exceed) their minimum daily requirements of nutrients as well as keep them close to the ideal of 5 on the Henneke Body Condition Scoring Chart (from 1 = emaciated to 9 = obese). Turnout and exercise also play a large role in a horse’s topline and other muscles, but that’s a different topic!

The sixth revised edition of Nutrient Requirements for Horses by the NRC lists the daily nutrient requirements for all stages of horses based on their mature body weight. I selected 500kg (1100lbs) for your mare.

While an adult horse in no work requires a minimum of 540 grams of crude protein a day, even during the first five months of pregnancy, the gestating mare already requires 630 grams of protein. Below is a table of the pregnant mare’s protein requirements as gestation proceeds:

Month of Gestation CP Requirement
5 mos 685 grams
6 mos 704 grams
7 mos 729 grams
8 mos 759 grams
9 mos 797 grams
10 mos 841 grams
11 mos 893 grams

While it may seem like the pregnant mare needs a lot more protein than the adult horse in no work, things really get exciting when you look at how much protein the lactating mare requires! Here is a table to prepare you for what you should be feeding once the foal is born:

Month of Lactation CP Requirement
1st 1535 grams
2nd 1530 grams
3rd 1468 grams
4th 1398 grams
5th 1330 grams
6th 1265 grams

To make this practical for you, let me take the 11 month value, 893 grams, and do a little math.

Let’s say you’re feeding 15 pounds of a 10 percent protein grass hay along with 5 pounds of a 14 percent crude protein fortified grain.

15lbs X 10% = 1.5 lbs protein in the hay

5 lbs X 14% = 0.7lbs protein in the grain

TOTAL Protein = 2.2 lbs, which is 1 kilogram, which is 1000 grams.

So for now, you are feeding your mare enough protein. However, once the foal is born and she begins lactating, she will need more. There are a couple of ways to do this. You can feed more hay and/or more grain (but no more than 5 pounds of grain at one meal), you can feed higher protein hay (such as alfalfa) and/or higher protein grain (such as a 16 percent crude protein product), or you can add in a high-quality protein supplement. Because you’ll want to involve your veterinarian during the last month of your mare’s gestation through the birth of the foal, I suggest asking him or her for suggestions on which of these strategies might be best to meet your mare’s protein requirements. Good luck!

While it’s difficult to answer your question without knowing exactly what you mean by a “bad incisor tooth,” I have to say I am unaware of any nutritional imbalances or deficiencies that would result in one tooth going bad. Hopefully, your veterinarian will be able to look at the tooth, determine what the problem is, treat it, and recommend a program to prevent future tooth problems. I can only suggest that you have your veterinarian examine your horse’s mouth at least once a year, performing any dental work deemed necessary. Some problems can be prevented by regular dental maintenance.

Otherwise, if you are feeding at least 1 percent, but preferably 2 percent, of your horse’s body weight per day in high-quality forage, making water and salt available at all times, and feeding at least the minimum amount (by weight) of grain that it says on the label, an adult horse in little to no work may not need anything else.

Cribbing is a tough issue because there doesn’t seem to be any consensus on what causes it or how to curb it. I consulted the sixth revised edition of Nutrient Requirements for Horses by the NRC for the most up-to-date information and here’s what I found:

Cribbing is a stable vice or stereotypie, which is defined as “apparently functionless, repetitive behavior.” Other stereotypies include weaving and stall-walking. Many of the interventions once used to arrest stereotypic behavior, such as punishment or physical prevention, have been recognized to be mostly ineffective and potentially detrimental to the horse’s welfare, especially if no attempt has been made to resolve the instigating cause.

Cribbing and other stereotypies may have breed, function, environmental, feed management, age or disease conditions associated with them. One study concluded that housing method, whether pasture, box stall or tie stall had little effect on eliciting abnormal behaviors, but that the form of the diet clearly affected behavior.

Approximately 10 percent of preweaning foals and 20 percent of postweaning foals crib and wood chew, leading investigators to suggest that creep feeding concentrate to hungry foals may cause stomach problems that lead to these abnormal behaviors. Cribbing and wood chewing have been associated with a lack of fiber or roughage. Cribbing horses have been shown to have a lower stomach pH, which may be due to too little fiber, too much concentrate and reduced saliva production.

Feeding too little hay, feeding hay rather than pasture and feeding only one type of forage have all been shown to induce or increase the risk cribbing and wood chewing. One study showed all horses, whether prone to stereotypic behavior or not, showed more abnormal behaviors as feeding frequencies of grain increased from two to four to six times per day.

It has been suggested that cribbing may have a neurochemical origin in addition to the predisposition that may arise through nutritional management.

How can you put all of this (somewhat contradictory) information to use: Although the editors of Nutrient Requirements for Horses fully admit there is little research to support them, these recommendations were listed: avoid creep feeding preweaning, minimize concentrates, supplement with antacid, maintain horses on pasture, increase the hay ration, feed the affected horse before the other horses, reduce the time the horse spends in the stable, increase the horse’s exercise, increase the horse’s social contact, and use a stable chain instead of a solid door so the horse has a varied view from its stall.

In your case, I specifically recommend turning your horse out on pasture to graze (preferably with a buddy or two), reducing the amount of grain you feed him and supplementing with fat and possibly other weight gain products, such as amino acids. You may also want to vary his forage by providing alfalfa or other type of hay. I hope some of these suggestions help!

I’m sorry, but I can’t find any research that suggests sunflower seeds can prevent colic. Sunflower seeds contain fat, protein, fiber, vitamins and minerals, but none of these nutrients strikes me as something that could help prevent colic. Because sunflower seeds do contain anywhere from 25 to 40 percent fat, mostly in the form of omega-6 fatty acids, they are fed to horses to put bloom in the coat and provide additional calories/energy. According to Kentucky Equine Research, if you are going to feed sunflower seeds to your horse, make sure you feed the black oilseed variety, not the striped confectionary, and start gradually, as with any new feed. Since there are no hard and fast guidelines for feeding sunflower seeds, they suggest no more than one pound (about two cups) of sunflower seeds per day, to prevent horses from developing a distaste for them and picking them out.

Congratulations on joining the ranks of official “horse owner!” I’m glad to see that you’re not only seeking out expert nutritional advice (that’s me), but also the wisdom of a professional trainer. I encourage you to read as much as you can about horses, horse training and especially horse nutrition, such as with AAEP’s Media Partners The Horse magazine and Equus magazine.

Here’s a quick Nutrition 101 for all my first-time horse caregivers:

Feed at least 1percent (preferably 2 percent) of the horse’s body weight each day in high-quality forage (hay or grass). For a 1,000 pound horse, that would be 10 to 20 pounds. Feed by weight, not by volume. So fill your coffee can with grain and weigh it on a kitchen scale or do what I do, use the produce scale at the grocery store! Then you’ll know if you’re feeding at least the minimum amount of grain recommended on the label, vital to meet vitamin and mineral requirements.

Feed at least two times per day (preferably three or four), and feed no more than 5 pounds of grain at one meal. Provide fresh, clean water and salt at all times.

Try to keep your horse’s body condition score around the ideal of 5 (from 1 = emaciated to 9 = obese). You can find pictures, descriptions and a chart by Googling “Henneke body condition score horse.”

Now for some specific advice for you: If you haven’t already formed a relationship with a local equine veterinarian and had a complete physical examination performed on your filly, there’s no time like the present. You may find out there’s a medical reason why your filly isn’t gaining weight, such as internal parasites, dental disease or other condition. Your veterinarian will work with you to set up a parasite control program, perform annual oral exam and floating, as well as provide vaccinations and other preventive health care.

Next, make sure you are feeding high-quality grass or alfalfa hay, and not old or overly mature forage with little nutritional value. If possible, keep grass hay in front of her at all times, and feed smaller, more frequent grain meals. Fat is an excellent source of additional calories, and now comes in many tasty forms for horses, such as fortified grain with added fat, fat-only supplements in pellets or powder, rice bran, flax seed products and vegetable oils. When adding anything new to your horse’s diet, start gradually and take two weeks to build to the recommended feeding amount.

Before adding any other supplements, I recommend talking to the trainer where your horse will be going soon. He or she may have a different feeding program than what your horse is on now and that program may be ideally suited to your filly. Plus, you’ll be feeding the same thing at home as at the trainer’s, which is a good idea (horses don’t like change!) Keep in mind that the environment has a lot to do with the ability of some horses to maintain weight. For example, if your horse lived in a herd and you brought her home alone, she may be pacing the fence burning calories looking for her friends. On the other hand, if she was used to being brought into a stall and fed individually, but now she’s turned out 24/7 with other horses and having to fight for her food, she is also burning calories.

I hope these suggestions help and good luck with your new filly!

Please review the other question and answer about intermittent upward fixation of the patella (the question asks about a Thoroughbred gelding that has luxation of his hind left stifle). In it, I explain just what this condition is and the different methods, in order, that are used to treat it.

While I encourage you to make sure your two-year-old is fed appropriately for his age and breed, especially when it comes to selenium (because the window between what is required and what is toxic is small) and trace minerals (because hay usually does not contain the minimum requirements for horses), I can find no scientific evidence that the condition is specifically linked to a deficiency in Se or other trace minerals.

Generally speaking, horses with a tendency to lock their stifles, have very upright hindlimb conformation, are not fit/conditioned, and may have long toes on their hind feet. Although there’s nothing you can do about his conformation at this point, it appears that you can provide your young horse with more exercise, as you mention his stifle locks up “after he had play time the time day before.” A horse this age should have “play time,” or turnout, every day. Be careful forcing him to exercise, however, as is suggested by veterinarians treating adult riding horses with this problem.

You may also find that more frequent hoof trimming, as well as shortening and squaring the hind toes, also helps. Of course, talk with your veterinarian about this problem, make sure he or she is on board with these recommendations and follow-up with your veterinarian if you feel further treatment is necessary to improve this condition.

Kudos to you for being a careful label reader! I contacted Freedom Health, the manufacturer of Succeed, for help with the answers to your two questions. Here is what their representative said:

"This customer should not switch off the Grand Complete Ultra, which contains joint support ingredients, vitamins and minerals that SUCCEED does not offer. It is not a problem to feed the yeast culture with SUCCEED. The types of products that we sometimes suggest not to use in conjunction with SUCCEED include pre/probiotics because they are usually unnecessary. That’s because we are reducing the amount of starch that reaches the hindgut and maintaining a neutral pH in the cecum, which should keep the bacterial populations in check. So, in the case of a probiotic, it is not necessary to add back the cultured bacteria. It is when starch reaches the hindgut and is rapidly fermented that the lactic acid drops the pH in the cecum, jeopardizing bacterial populations.

As far as the price, only SUCCEED has the unique combination of ingredients to promote total digestive health. We have the exclusive right to the source of our polar lipids and Beta-glucan. As is the case with a lot of ingredients, not all things are created equal!"

When I evaluate a product and its manufacturer, I ask myself these questions:

1) Do they have a reputation to protect or are they out for a quick buck?

2) Are they following supplement advertising guidelines or are they making bold, inappropriate claims?

3) Is a guaranteed analysis provided?

4) Are the product’s complete ingredients listed?

5) Has independent scientific research on the product been performed?

When I visited the company’s website, I found both some positive answers to these questions and some negative answers. I encourage you to visit their website and draw your own conclusions.

Next I Googled “xango juice,” and found a 2006 article on WebMD that said the FDA has warned the makers of XanGo Juice to stop making health claims about the juice, voicing “serious concerns” about those claims. These claims included prevention of atherosclerosis, bacterial infection, glaucoma, cataracts and gum disease, among others. XanGo said the non-compliant literature was not produced by the parent company, but by a distributor. Currently, their website says:

“Research shows xanthones possess potent antioxidant properties that may help maintain intestinal health, strengthen the immune system, neutralize free radicals, help support cartilage and joint function and promote a healthy season respiratory system.”

I also visited PubMed, an excellent resource to look up scientific articles. There were 45 entries for “mangosteen,” which is the name of the fruit, and they ranged from studies examining the active ingredients of the fruit to those evaluating its use in heart disease, acne, gum disease and more. There is an excellent article by Marcason W., in the June 2006 issue of the Journal of American Dietetic Association called “What are the facts and myths about mangosteen?” You can do this article search yourself by going to www.pubmed.com.

So, to answer your questions, unfortunately, little information is available on the composition of mangosteen other than it possesses xanthones, which are potent antioxidants. I can’t tell you how much sugar the fruit contains. I can tell you there are no published studies in horses to date, although people are using on horses for a variety of problems.

Thanks for these two questions. They are ones I get a lot. Since you asked about a specific product, Cosequin, I decided to let a representative from Nutramax Laboratories provide the answer:

”Cosequin has no known contraindications. It has been evaluated in two safety studies in horses, including a study in which, Cosequin ASU was given at up to five times maintenance levels for 84 days. This level provided 36 g glucosamine daily. In both safety studies, no adverse effects on blood
sugar levels or any clinically significant effects on any biochemical parameter were seen. In a study with human diabetics who were well-controlled, no effects were noted on long-term blood glucose control or on diabetes management. It is, however, always recommended that any overall plan include a consultation with a veterinarian.

It is fine to administer two scoops in one feeding if that is more convenient. There is no known difference in benefit between dividing the amount into two administrations or giving all at once.”

I hope this relieves any worries you may have!

Unhealthy hooves seem to be a common question this month! First, reevaluate your horse’s basic diet to make sure he is receiving at least 1%, but preferably 2% of his body weight each day in good quality forage (hay or grass). Then, make sure he is getting at least the minimum daily requirements of vitamins and minerals by giving the suggested feeding amount of a fortified grain, ration balancer or vitamin/mineral supplement. I also urge you to evaluate his environment, because a horse that goes back and forth from wet to dry is prone to developing cracks and other hoof issues. If everything appears to be in order, then read my previous answer to whether supplementing with biotin will improve hoof hardness (it does!)

A horse with chronic diarrhea can be very frustrating, especially one that’s so young and has suffered with it all her life. While it’s a good sign that she’s healthy otherwise (I assume good weight and energy), I’m pretty sure there’s nothing over-the-counter that I can recommend to you that will help her. The best advice I can give you is to ask your veterinarian to refer you to a teaching hospital/veterinary school and have a complete diagnostic workup performed on your mare. They may start over with basic bloodwork and fecal examinations, but will also perform more specialized tests such as absorption studies, response to prescription medications designed to slow GI motility, intestinal biopsies and more. Although you may never find out the actual cause of the diarrhea, the internal medicine specialists at a referral center may be able to find a medication and feeding regimen that firms her stool.

First, I need to make a few comments about your “grain.” Trotter by Blue Seal is not actually a “grain,” but a complete feed, basically hay and grain together in a bag. It is a high fiber product used for horses that cannot have hay because of poor teeth or respiratory allergies or other reasons. It must be fed in much larger amounts than true fortified grains in order to provide the horse’s minimum vitamin and mineral requirements. In fact, the label for Trotter says to feed one to 1.25lb/100lb body weight daily. That’s 10 to 12.5 lbs for a 1000 pound horse just for maintenance, not even light work. Since one quart of this product equals 1.45 lbs, your horse is getting very little if any selenium from this product.

On the other hand, Charger by Blue Seal is a true fortified grain, or concentrate, designed to be fed in much smaller amounts to horses in heavy work, pregnant, lactating or growing. It’s at the complete other end of the spectrum! There is no suggested feeding range for maintenance of mature horses because it is not intended to be fed to this group of horses. So rather than combine two products developed for two very different groups of horses, my suggestion to you is to select the Blue Seal product that best matches your horse’s age and use and feed the minimum the bag suggests. Then if he needs more calories, you can increase the amount (never more than five pounds of grain per feeding). If he needs less calories than the minimum on the bag, he should probably be switched to a ration balancer (protein, vitamin, minerals) or a vitamin/mineral supplement, both of which reduce the calories but keep the nutrients.

Once you get your horse back on track with his basic nutrition (including at least 1% but preferably 2% of his body weight in forage daily), we can discuss his specific selenium requirements. The sixth edition of Nutrient Requirements for Horses estimates the horse’s daily selenium requirement at 0.1mg/kg of the ration, which, when you do the math, comes out to about 1mg of selenium per day, from all feedstuffs combined. However, keep in mind this is the minimum level required to prevent obvious signs of deficiency. Janicki and others have shown that 3mg of selenium per day may provide benefits beyond those necessary to support life, such as improved immune status. Research by Pagan and others suggests selenium-enriched yeast is more bioavailable than either sodium selenite or sodium selenate, two common inorganic sources of supplemental selenium.

Handy tip: 1 ppm = 1 mg/kg and ppm (X) 0.001 = % or % (X) 10,000 = ppm

I assume you’ve had your stallion thoroughly examined by a veterinarian who specializes in reproductive physiology (a theriogenologist). If not, this should be your first step. An equine theriogenologist may have some additional ideas for handling and processing your horse’s semen to extend its life.

Below is summary of a research study evaluating whether a specific omega-3 fatty acid, docosahexaenoic acid (DHA) had any effects on semen quality. It turns out that supplementing with DHA improves the ratio of DHA to DPA (docosapentaenoic acid or DPA, an omega-6 fatty acid), leading to increased fertility, especially in marginally fertile stallions. That is, stallions that did not have fertility issues, didn’t improve much, but stallions whose sperm had poor tolerance to cooling or freezing, benefited significantly from DHA supplementation. The take-home message for you is

1). Have your stallion evaluated to determine exactly what the problem with his semen is and;
2). Be sure you are feeding the appropriate amount of the specific omega-3 fatty acid DHA, while NOT providing additional omega-6 fatty acids, which are linked to a decrease in fertility.

Effect of feeding a DHA-enriched nutriceutical on the quality of fresh, cooled and frozen stallion semen. Brinsko et al, College of Veterinary Medicine, Texas A & M University, 2005.

A group of stallions was fed a diet top-dressed with 250g of a DHA-enriched nutriceutical for 14 weeks. Sperm motion characteristics in fresh semen were unaffected by treatment. After 24h of cooled semen storage, total and progressive motility did not differ between treatment groups, but sperm from stallions fed the nutriceutical exhibited higher velocity and straighter projectory. After 48h of cooled storage, increases in the percentages of sperm exhibiting total motility, progressive motility and rapid motility were observed when stallions were fed the nutriceutical. For a subset of 4 stallions whose progressive sperm motility was <40% after 24h of cooled storage when fed the control diet, feeding the nutriceutical resulted in improvements in progressive motility of sperm after 24h and 48h of storage. Feeding the nutriceutical resulted in similar improvements in motion characteristics being observed in frozen-thawed semen. While it appears that feeding the nutriceutical may improve the motion characteristics of cool-stored stallion semen, it may be most beneficial for stallions of marginal fertility whose sperm do not tolerate the rigors of cooling and storage. The nutriceutical also appeared to improve the freezability of semen. More dramatic improvements in semen quality may be observed if modifications in the main fat content of the diet are incorporated with the DHA supplement.

You left out one important component of your horse’s diet: his forage, whether grass or hay. If you are going to spend the time and money to analyze what your horse is getting from his feed and supplements, you have to include what he is getting from his forage as well, since that is the bulk of his diet.

Also, ration analysis can tell you the levels of protein, various carbohydrates, fat, macro and microminerals, and vitamins that are in the feedstuffs your horse eats. However, they typically do not analyze for herbs, so you will have to look elsewhere for that information. If you are working with a holistic veterinarian to design your horse’s health and nutrition program, he or she may be able to point you in the right direction.

After you receive the results of your ration analysis, you may want to consult with a veterinarian or nutritionist to help make sense of all the numbers. If you have a veterinary or agriculture school in your state, I suggest starting there. Sometimes county extension offices can be very helpful. Depending on the brand of grain you feed and how many horses at your barn are on it, local sales representatives may be able to analyze your forage and work with you to balance the entire ration. Here are some websites to get you started:

www.equi-analytical.com - An excellent resource for feed analysis and ration formulation.

www.uckele.com - Uckele Health and Nutrition offers hay analysis and computerized ration balancing.

www.ker.com - Kentucky Equine Research is the official equine nutritionist of the USEF.

www.acvn.org - Is the American College of Veterinary Nutrition, veterinarians board-certified in nutrition.

www.aavn.org - is the American Academy of Veterinary Nutrition, an association of veterinarians and animal scientists with a special interest in nutrition.

You are right on track with biotin as a supplement to support healthy hoof growth! While some research suggests other nutrients (such as methionine, lysine, copper and zinc), are also beneficial when it comes to building strong, healthy hooves, there is plenty of research to back up your belief that biotin is the main ingredient to have on board. Most of the studies below conclude that 20mg of biotin per day continuously (minimum five months) is an appropriate amount to supplement. Happy hoof-building!

Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial (Reilly et al, 1998)

Biotin supplementation (0.12mg/kg BW) produced a significantly higher growth rate of hoof horn in this trial. Treatment animals had a 15% higher growth rate of hoof horn and 15% more hoof growth at the midline dead center, after 5 months of biotin supplementation compared to control ponies.

Histological and physical assessment of poor hoof horn quality in Lipizzaner horses and a therapeutic trial with biotin and a placebo (Zenker et al, 1995)

After 19 months of biotin treatment (20mg/day), the horn quality showed a small, but significant improvement shown by comparing the microscopic tissue structure before and after treatment, and by comparing treated animals to the placebo group.

Hoof horn abnormalities in Lipizzaner horses and the effect of dietary biotin on macroscopic aspects of hoof horn quality (Josseck et al, 1995)

Daily administration of 20mg biotin to a test group of horses and a placebo to a control group showed that after 9 months, the test group had significantly improved compared to the beginning of the trial and the placebo group. In the test group, further improvement was observed during the following 5 months and, subsequently, the same good level of hoof condition was maintained over 3 further years of observation. It was concluded that continuous dietary supplementation with biotin at a daily dose of 20mg is indicated to improve and maintain hoof horn quality in horses with less than optimum quality hoof.

The long-term influence of biotin supplementation on hoof horn quality in horses (Geyer et al, 1994)

The influence of dietary biotin in horses with brittle hoof horn and chipped hooves was investigated over a period from one to six years. Horses received 5mg biotin per 100 – 150kg body weight daily. The hoof horn condition of the biotin-supplemented horses improved after 8 to 15 months of supplementation as determined by micro- and macroscopic examinations. The hoof horn condition of most control horses remained constant throughout the study. Hoof horn condition deteriorated in most horses after biotin supplementation was reduced or terminated. It was concluded that biotin should be continuously supplemented at the full dosage in horses with severe hoof horn alterations.

Effect of dietary biotin supplement on equine hoof horn growth rate and hardness (Buffa et al, 1992)

Over a 10-month period, 24 randomly selected riding horses were fed various amounts of biotin. Statistically significant improvements in growth rates and hardness of hooves were produced by biotin supplementation. Greater growth rates and hardness were achieved at a daily dose of 15mg than at 7.5mg.

Clinical observations on the response of equine hoof defects to dietary supplementation with biotin (Comben,1984)

It was concluded that dietary supplementation with 10 to 30mg/biotin/day (depending on bodyweight) for not less than six to nine months, is a useful treatment to support horses with weak hoof horn, which becomes misshapen and crumbles around the lower parts of the hoof walls.

First, let me praise you for your hard work in providing a complete and balanced diet for your horse! Next, let me encourage you to turn your horse out as much as possible. Unless there is a medical reason against it or your boarding situation prevents it, the more your horse can exercise at will in fresh air with other horses, the better! I say this because in researching answers to your two questions, I was unable to provide you with evidence proving he needs more than the four hours of turnout daily he gets now.

The short answer to your first question is: yes, the amount of sunlight your horse is exposed to through fours hours of turnout per day is probably enough to meet his minimum Vitamin D requirement. While the sixth edition of Nutrient Requirements of Horses only said “There are no reports of Vitamin D deficiency to date in horses maintained in practical settings with some exposure to sunlight,” several other sources said “a few hours of sunlight a day” and even “as little as one hour of sunlight a day” would probably be sufficient. If you choose to supplement to ensure healthy calcium metabolism (the primary role of Vitamin D), 300IU/100lb BW, is the recommended amount, or about 3000IU for a 1000lb horse.

Now to your second question! Circadian rhythm is the roughly 24-hour cycle in physiological processes of living beings, both plants and animals. Some of these physiological processes include: sleep/wake, body temperature, thirst, appetite, brain wave activity, hormone production and cell regeneration. Circadian rhythm is generated from within the animal itself, but it can be altered by external cues such as daylight, temperature, feeding/fasting periods and other stimuli. As long as your horse receives some light each day, he should have a healthy Circadian rhythym.

I encourage you to read my answer to some of the previously answered questions, then consider this approach. Although we know the risk factors for osteoarthritis: genetics (conformation, OCD), improper shoeing, excessive weight, acute injury, chronic wear and tear, we don’t know exactly when degeneration of the articular cartilage begins. One of the principles of joint supplementation is to have the building blocks of healthy cartilage and synovial fluid on hand before they are needed. This way, when and if conditions lead to breakdown of joint tissue, glucosamine, chondroitin sulfate and hyaluronic acid will be immediately available for rebuilding.

Another principle of joint supplementation comes from understanding that these molecules do more than make up the structure of joint tissue, they may actually help slow or delay destruction. For example, several studies have shown that glucosamine not only stimulates the production of chondroitin sulfate, it also inhibits free radicals and enzymes that break down cartilage. Likewise, chondroitin sulfate not only stimulates the production of hyaluronic acid and proteoglycans, it also inhibits enzymes that break down cartilage.

While I can’t recommend a specific joint supplement, I can provide you with tips on reading supplement labels and evaluating manufacturers. Try to choose companies that:

- Provide a guaranteed analysis. This shows the minimum amount of each nutrient.
- List their product’s complete ingredients on the label.
- Have performed independent scientific research on their product and are willing to share that information (while rare in the industry, it does happen).
- Have a reputation to protect, and aren’t willing to risk everything for a quick buck.
- Don’t make bold claims or direct references to curing or treating disease on the label—this is the surest sign of a bad actor.

Another key sign of a high quality company is membership in the National Animal Supplement Council (NASC). The NASC is a non-profit organization formed by a group of supplement manufacturers to bring some level of accountability to the industry. The NASC has implemented standards for labeling and manufacturing so that consumers will know what they are getting for their supplement dollar.

Only NASC members companies that have been audited by the NASC for manufacturing, labeling and adverse event reporting are permitted to use the NASC Seal of Quality. Membership in the NASC (and permission to use the Seal of Quality) is a good indicator of a supplement company’s willingness to adhere to standards of quality. However, it is not a foolproof method of selecting a supplement because many reputable companies have chosen not to belong, yet still make a quality product.

As always, involve your veterinarian when making any decisions that affect the health of your horse. Good luck and may you have many more productive years with your horse!

I’ll get to your two questions eventually, but first I’d like to talk about your horse’s overall health and nutrition. Has your veterinarian performed a complete physical examination on him, including a thorough oral exam, bloodwork and quantitative fecal egg counts?

If your horse checks out okay, the next thing to consider is how much and what kind of hay you’re feeding. Horses should receive at least one percent but preferably two percent of their body weight per day in good quality forage (hay or grass). Let’s say your Thoroughbred weighs 1200pounds, he would need 12 to 24 pounds of hay per day. To know if you’re really feeding this much, I recommend actually weighing your hay. You can do this by hanging several flakes from a fish scale using baling twine, or by weighing yourself on a regular bathroom scale then weighing yourself holding the hay and subtract the difference. Rather than feed a large amount of hay in just two feedings, spread his daily allotment out over three, four or more feedings. That way, he may be less apt to “trash” it. If you can keep it off the ground, that’s even better, and don’t shy away from alfalfa hay. As long as you don’t feed it ad lib and your horse doesn’t have any kidney problems, it’s a tasty source of nutrition that helps a lot of horses, especially older ones and picky eaters, put on weight. Soaked alfalfa cubes are especially delicious!

Now let’s look at your fortified grain, or concentrate. I see that you’re feeding Blue Seal Vintage Senior, which appears to contain high-quality protein, added fat and reduced starch and sugar. The label says you should feed a minimum of 0.5 pound per 100 pounds of body weight (that’s to make sure he’s getting his minimum requirements of vitamins and minerals). Again, if we use 1200 pounds for your horse, that’s at least six pounds of this grain per day, preferably divided into several feedings. However, a horse in moderate work can be fed 1.25 pounds per 100 pounds of body weight, which would be 15 pounds of this grain (remember never to feed more than five pounds of grain at one meal). Because you’re also feeding Triple Crown Senior Formula (which has the same feeding rate), I suspect you’re NOT giving your horse the minimum amount of either product.

I suggest choosing just one of these products and feeding it according to the directions on the label. That way, you’ll be providing your horse at least the minimum levels of vitamins and minerals he needs and won’t run the risk of unbalancing the diet by combining products from different manufacturers.

Now we can talk about supplements! I think the addition of a daily dewormer is a good idea, because some horses have shown increased feed efficiency through its use. I like that your fortified grain has fat in it, but you can add more if you like, as long as you add it gradually and don’t go over about a pound of fat or two cups of oil per day. There are several choices for adding fat, including:

1) Special commercial supplements that run 25%, 40%, even 90+% fat

2) Rice bran or rice bran-based products

3) Flax seed or flax seed-based products

4) Vegetable oil

5) Powdered fat

If you add fat to your horse’s diet, I recommend adding Vitamin E as well, as an antioxidant to scavenge free radicals created from the oxidation of this fat.

Some horses, especially Thoroughbreds, gain weight via muscle when amino acids are added to the diet, especially the limiting ones, lysine and methionine. There are also a variety of supplements intended to help build muscle, such as HMB and Gamma Oryzanol (conveniently found in rice bran!) although research supporting their use is limited at this time.

Some horses just need to build their appetite, and a recent study showed bee pollen increased feed intake and nutrient retention. Another study identified flavor preferences in horses to be (in order): fenugreek, banana, cherry, rosemary, cumin, carrot, peppermint and oregano. You may try adding one of these flavors to your horse’s feed or purchasing a supplement with one of these flavors as an ingredient to see if he’ll eat more.

Finally, you may want to provide pre- and probiotics to your horse. Prebiotics are the “food” for the probiotics, which are the “good bugs” in the intestinal system. This may also help with feed efficiency. The Triple Crown feed you’re giving contains one of each, but you may want to provide several different strains.

My last piece of advice is to try all these different suggestions one at a time. If you throw everything but the kitchen sink at your horse—and he improves—you won’t know what worked and you may be spending a lot of time and money on products he doesn’t need.

I’m going to assume your horse has upward fixation of the patella, not patellar luxation, as this condition is uncommon in adult horses and usually only seen in foals (especially miniature foals) at birth.

It is generally accepted that horses that “lock” their patellas, that is, whose medial patellar ligament gets hooked over the medial trochlea of the femur, improve with conditioning or fitness training. Since it is the quadriceps, or the muscles on the front of the horse’s legs that most need to be strengthened, hill work is particularly recommended, as is driving, or pulling.

If your horse improves with additional, controlled exercise, then no more treatment may be necessary. However, if there is little to no improvement, your veterinarian may suggest other treatments to help your horse. These include corrective shoeing, estrogen therapy, infusion of a counterirritant or “blister,” or, as a last resort, medial patellar desmotomy surgery, where the ligament that gets hooked over the femur is cut.

I have been asked before if a supplement, containing silica and collagen, would be appropriate for a horse with upward fixation of the patella and my answer is: I don’t know. On the one hand, part of the conditioning or fitness training is to develop stronger tissues, and having the building blocks of strong ligaments available during this time would make sense. On the other hand, if the ligament develops without corresponding muscle development, would the problem get worse? I do think that supplementing with anti-inflammatories may be indicated, but ask your veterinarian before starting your horse on one.

Congratulations on your success in eventing and on having such a happy, healthy partner! You sound like an intelligent, caring horsewoman, so I took the time to actually look up some research papers for you to read yourself and make an intelligent, informed decision about the benefits of oral joint supplements.

The following papers have all been presented at the AAEP Annual Convention, meaning they have been peer-reviewed by other veterinarians and scientists for quality of research:

Effects of an Oral Nutraceutical on Clinical Aspects of Joint Disease in a Blinded, Controlled Clinical Trial: 39 Horses (2007) - Keegan and others from the College of Veterinary Medicine at the University of Missouri concluded that oral administration of a product containing cetyl myristoleate, glucosamine HCl, MSM, hydrolyzed collagen and other ingredients had beneficial clinical effects on horses with naturally occurring osteoarthritis.

Review of Glucosamine-Containing Oral Joint Supplements: Are They Effective in the Horse? (2006) - In this paper, Weese reports on a number of studies in both humans and horses that conflict regarding the efficacy of glucosamine (some say they work, some say they don’t). He concludes that veterinarians and horse owners who would like to give glucosamine joint supplements, should familiarize themselves with nutraceutical products with proven quality and give therapeutic doses (10g orally per day) by carefully reading the label guidelines and ingredients.

Effect of Glucosamine and Chondroitin Sulfate on Mediators of Osteoarthritis (2006) - A study by Neil and others showed that glucosamine significantly reduced a number of mediators of osteoarthritis, but chondroitin sulfate did not (at the concentration tested). They mention other studies that showed glucosamine and chondroitin sulfate in combination seem to be more effective than either compound alone.

Double-Blind Study of the Effects of an Oral Supplement Intended to Support Joint Health in Horses with Tarsal Degenerative Joint Disease (2002) - Dr. Hilary Clayton’s group at the College of Veterinary Medicine at Michigan State University, demonstrated that horses with hock arthritis showed a significant reduction in gait asymmetry after receiving an oral joint supplement for just two weeks as compared with placebo.

Evidence of the Oral Absorption of Chondroitin Sulfate as Determined by Total Disaccharide Content After Oral and Intravenous Administration to Horses (2001) - Eddington and her co-authors provided the first proof of the bioavailability of chondroitin sulfate in this paper. Their work suggests that the molecule is absorbed after oral administration.

The conclusion I draw from these and other research papers, is that there is some evidence that some ingredients in some joint supplements are effective. I recommend working with your veterinarian to develop an overall wellness plan to maintain your horse’s health and soundness as long as possible. This may include FDA-approved pharmaceuticals like the Adequan that you mentioned, and it may also include over-the-counter nutraceuticals as you see fit.