"If horses are calorie deficient—not taking in enough fuel to run their bodies—they lose weight, present in poor condition, and may lack energy. These are problems that can’t be helped with any amount of supplemental vitamins or minerals.” In the past few decades, the equine health market has seen a significant uptick of myriad supplements that purport to do just about anything that a horse might need—to support, enhance, or boost everything from hooves to intestines to joints to hair coat. By definition, a supplement is something that is provided to complete something, to make up for a deficiency, or to extend or strengthen the whole. An entire generation of horse owners has been sold on the idea that various supplements added to the horse’s diet purport to do most or all of these things (as well as many others). However, considering that horses are well equipped to provide for all of their nutritional needs with good quality forage and water, such ideas shouldn’t be assumed to be absolute truth. Equine health information providers should consider several factors before riding the supplement wave. Overlooking a common culprit The most common deficiency seen in horses is a lack of adequate calories. Horses often are not given enough feed for the work required of them. Exercise, lactation, and growth all require a great deal of calories. As such, horses that work hard may require more feed than what is routinely given to them, but when talking about supplements, most people aren’t thinking of calories. Still, if horses are calorie deficient—not taking in enough fuel to run their bodies—they lose weight, present in poor condition, and may lack energy. These are problems that can’t be helped with any amount of supplemental vitamins or minerals. However, horse owners generally overlook a lack of feed as the reason behind low or lack of energy and weight loss in their horses. Discovering that your animal is losing weight because he’s not getting enough to eat is sort of like finding out that your washing machine doesn’t work because you forgot to plug it in. You’re happy to find out what the problem is, but it’s kind of embarrassing, and you’d really rather it be something else. Horses rarely are deficient in anything other than energy, but there are exceptions. For example, certain soil in parts of the U.S. is deficient in selenium, and horses in these areas may benefit from selenium supplementation. It is very difficult to create a diet of normal horse feed that supplies enough calories for their systems to run but that also is deficient in the protein, vitamins, or minerals that fulfill important functions in horses. However, providing more of any of these substances than what is needed for a particular function will not cause the horse to perform that function better. Nor are vitamins and minerals necessarily benign—vitamin and mineral toxicities have been reported in horses (albeit rarely). Horses' nutritional needs are met best through good quality feed and water. Of course, there’s no way to measure a horse’s energy levels. But there is a big difference between the energy supplied by feed and “feeling energetic.” This latter concept is what horse owners fret over, and there are many products—mostly vitamins and minerals—to assist horse owners with their fretting. Well-meaning owners also commonly provide dietary protein supplements to their horses. Unquestionably, these animals need protein to build body tissue, especially those that still are growing. Adult horses need protein, too, but not very much. Further, protein requirements don’t increase when they exercise. Extra dietary protein is neither beneficial nor harmful; it’s merely digested and converted to energy. Do your research While many supplements exist for many conditions, the equine supplement industry essentially is unregulated. Claims can be vague, and proof that the products perform per their claims is sparse. In fact, if these products did make specific claims, they would be regulated as drugs. In some cases, levels of certain ingredients may not be related to a horse’s dietary needs. In others, e.g., glucosamine or chondroitin sulfate, ingredient levels may be hundreds of times less than those shown to have an effect in in vitro studies. As such, veterinarians may find themselves recommending or opining about products that offer little to no assurance of purity, content, or efficacy. Supplement product labels should indicate not only the products’ purpose and intent but also what constituent of each supplement is supposed to cause the beneficial effects. Some supplements don’t even list ingredients. In my opinion, most horses don’t require dietary supplements. Assuming that they’re getting enough good quality feed to maintain a healthy weight, they’re also probably getting enough of everything else. Dr. David W. Ramey is a Southern California equine practitioner who specializes in the care and treatment of pleasure horses. Visit his website at doctorramey.com. Columnists’ opinions do not necessarily reflect those of Veterinary Practice News.
