The EPSM Diet for Horses

A specialized low-carbohydrate, high-fat diet, when combined with exercise, has been shown to significantly alleviate the symptoms of equine polysaccharide storage myopathy, or EPSM. By implementing a strict exercise regimen and some simple dietary changes, many horse owners can expect their EPSM-affected horses to return to a useful and productive life.

  1. EPSM

    • EPSM is a metabolic muscle disease that can cause tying up, muscle wasting, weakness, poor performance, stiff gaits or the inability to rise from a recumbent position. The signs of EPSM are often evident when horses are returned to work after an extended rest period. Commonly seen in heavy draft horse breeds, EPSM has been identified in smaller horse breeds as well. A veterinary diagnosis can be made through a physical exam, the evaluation of muscle enzymes in blood samples and through a muscle biopsy, according to Kansas State University College of Veterinary Medicine.

    Dietary Goals

    • According to Dr. Beth Valentine, DVM, Ph.D., many EPSM cases show drastic improvement through dietary therapy. The basis of the horse's diet should be high-quality hay, she specifies, with 20 to 25 percent of the total daily calories consisting of fat. Carbohydrates should be removed entirely. Vitamins, particularly Vitamin E and Selenium, should be added to replace those normally found in horse feeds. Although the diet is safe for all horses, Valentine recommends horse owners consult with their veterinarian during any dietary changes.

    Carbohydrates

    • Veterinary research indicates that horses suffering from EPSM do not gain muscle energy from carbohydrates. Instead, these unused carbohydrates accumulate within the muscle cells, causing stiffness and pain. This means that typical horse feeds, including grains, commercial feed pellets or sweet feed, should be removed from the EPSM horse's diet. Grain or feed can be replaced with soaked alfalfa cubes, alfalfa pellets or soaked beet pulp. These simply add bulk, however, and do not serve as a caloric replacement for the carbohydrate-rich feeds, according to Rural Heritage Vet Clinic.

    Fats

    • Fat is added to the EPSM diet to replace the calories normally derived from carbohydrates. To provide the necessary 20 to 25 percent of total daily fat to the diet, corn or vegetable oil can be added. Because most EPSM horses require at least 1 lb. of fat per 1,000 lbs. of horse weight, two cups of oil or other fat source should be mixed with the soaked alfalfa cubes, alfalfa pellets or soaked beet pulp. Fat should be increased gradually to help the horse adjust to the new diet, says Rural Heritage Vet Clinic.

    Exercise

    • Dietary changes alone are not enough to prevent EPSM-related episodes. Daily exercise, whether through lunging, riding or pasture turn out are crucial to alleviate symptoms. Regular exercise allows the horse to maximize the use of the added fat calories and prevents a recurrence of symptoms. Work should be added gradually to the EPSM horse's schedule to avoid overexertion. Typically, horses can begin with brief lunging sessions that gradually increase in time and intensity as the horse gains muscle strength and endurance, says the Kansas State University College of Veterinary Medicine.