The Horse

MAR 2018

The Horse:Your Guide To Equine Health Care provides monthly equine health care information to horse owners, breeders, veterinarians, barn/farm managers, trainer/riding instructors, and others involved in the hands-on care of the horse.

Issue link: https://thehorse.epubxp.com/i/936432

Contents of this Issue

Navigation

Page 29 of 115

30 TheHorse.com THE HORSE March 2018 "Our research relies heavily on samples submitted to our laboratory, and the bulk of those are from horses suspected of having PSSM or other causes of tying- up," says Valberg. "We are grateful for these samples, of course, but what we are in dire need of is samples from healthy horses, apparently free from PSSM, to compare our abnormal samples to." Once her team has accumulated a "library" of samples, they can compare normal and abnormal samples to help address their remaining questions about PSSM, she says. For instance, why does having an accumulation of polysaccha- rides in muscle tissue cause muscle dis- solution? One hypothesis thrown around over the years is that the polysaccharide inclusions (abnormal structures) disrupt the muscle cells' ability to contract. "We don't exactly know why having too much glycogen causes ER, but my research team has been working on answering this question," says McCue. "We hypothesize that too much glycogen causes the muscle cell to think it doesn't need to generate energy—a sort of nega- tive feedback loop. We have some data to support this hypothesis and hope to submit a paper soon for publication." With owner and veterinary assistance researchers like Valberg and McCue can continue toiling in their laboratories, find- ing new pieces of information to add to their already impressive knowledge base. For additional information on PSSM, watch Valberg's free webinar at MyHorseUniversity.com/single-post/ PSSM-Disease or listen to her describe the disease at TheHorse.com/34071. h 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 Valberg's recommendation, horses should only consume hay that's <12% non- structural carbohydrates. "Again, your local extension office can recommend a laboratory capable of conducting hay analysis," says Crandell. "It's 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 nutritionist's help, to ensure they are both appropri- ate for the horse and that you're 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, MSc

Articles in this issue

Links on this page

Archives of this issue

view archives of The Horse - MAR 2018