b'Help! How Do I Feed My PSSM Horse?Stephanie Valberg, DVM, PhD, Dipl. ACVIM, ACVSMR, the Mary Anne McPhail Dressage Chair in Equine Sports Medicine at Michigan State University, urges owners to seek the assistance of a reputable equine nutritionist to fine-tune their PSSM horses diets to meet their individual needs. The equine extension specialist for your state may be either able to help with dietary advice or recommend an independent nutritionist, says Kathleen Crandell, PhD, an equine nutritionist with Kentucky Equine Research, in Versailles. If a feed company has an equine nutritionist, they may also be able to help with finding an appropriate feed for a PSSM horse.Extension specialists do not charge a fee for their services, and certain feed and nutrition companies offer complimentary advice. Independent nutritionists will, of course, charge for their services. As per Valbergs recommendation, horses should only consume hay thats <12% non-structural carbohydrates. Again, your local extension office can recommend a laboratory capable of conducting hay analysis, says Crandell. Its important to ask whether that facility checks for both starch and sugar (starch + sugar = NSC), as not all forage labs have the proper equipment for this.A company called Equi-Analytical (equi-analytical.com)analyzes starch, water-soluble carbohydrates, and ethanol-soluble carbohydrates, she adds. They also have a special carb pack option for horse owners only interested in starch and sugar content. Commercial PSSM feeds and ration balancers are also available.Ration balancers are ideal for many PSSM horses because they are low calories, fairly low-starch, and are low intake, which means that horses ingest few calories and starch, yet receive the required nutrients often lacking in an all-forage diet, says Crandell, adding that owners can also look for manufactured feeds formulated for PSSM horses that have higher caloric needs. With these products, always check the starch and sugar levels in combination with the feeding rate, preferably with an equine nutritionists help, to ensure they are both appropri-ate for the horse and that youre feeding them properly. Finally, while Valberg and others recommend supplementing PSSM horses diets with oil for added fat, owners need to monitor the balance of omega-3 and -6 fatty acids when doing so. When supplementing with vegetable oil it, is always a good idea to keep in mind that some oils, such as corn and sunflower, are high in the pro-inflammatory omega-6 fatty acids and nearly void of anti-inflammatory omega-3 fatty acids, says Crandell. Consider balancing the ratio by using at least some oils high in omega-3 fatty acids, such as flax or fish oil.When feeding a high-fat diet, consider offering vitamin E for its antioxidant properties. Nutritionists recommend giving 1-1.5 IU of vitamin E for every milliliter of oil being fed, says Crandell.Stacey Oke, DVM, MScOur research relies heavily on samplesWe dont exactly know why having submitted to our laboratory, and the bulktoo much glycogen causes ER, but my of those are from horses suspected ofresearch team has been working on having PSSM or other causes of tying- answering this question, says McCue. up, says Valberg. We are grateful forWe hypothesize that too much glycogen these samples, of course, but what we arecauses the muscle cell to think it doesnt in dire need of is samples from healthyneed to generate energya sort of nega-horses, apparently free from PSSM, totive feedback loop. We have some data compare our abnormal samples to. to support this hypothesis and hope to Once her team has accumulated asubmit a paper soon for publication.library of samples, they can compareWith owner and veterinary assistance normal and abnormal samples to helpresearchers like Valberg and McCue can address their remaining questions aboutcontinue toiling in their laboratories, find-PSSM, she says. For instance, why doesing new pieces of information to add to having an accumulation of polysaccha- their already impressive knowledge base. rides in muscle tissue cause muscle dis- For additional information on solution? One hypothesis thrown aroundPSSM, watch Valbergs free webinar at over the years is that the polysaccharideMyHorseUniversity.com/single-post/inclusions (abnormal structures) disruptPSSM-Disease or listen to her describe the muscle cells ability to contract.the disease at TheHorse.com/34071. h30TheHorse.comTHE HORSE March 2018'