PSSM (PolySaccharide Storage Myopathy) is a genetic change in some horses that prevents the muscle cells in affected horses from accessing their glycogen storage. The time-tested workaround is to feed a diet high in fat.

Horses make fat from the microbial digestion of cellulose. Be sure to soak the hay to remove the free sugar. Limit the hay intake so that there is body fat loss. Aim for about 1.5% of the body weight and work from there. Note: no animal needs to eat sugar. All required sugar is made by the animal, including horses. Be sure to listen to this week’s podcast.

The first action is to see if the horse is doing well on the diet he is on. If so, proceed cautiously, as others have worked to diminish the cramping. If he is uncomfortable and you want to change things, remove all inflammatory ingredients (grains, byproducts, seed oils). Observe. Reduce or eliminate all extra sugar from the diet (soak the hay, no treats, limit turnout). Observe. Add soybean meal slowly by ½ cup measures to help build his muscles. More muscle = more glycogen storage, which may or may not help. Also, the protein will help with their skin allergies, but this will take TWO summers – yes, that long, but with improvement in the first summer. Observe.

Write everything you do into a dated journal and report what you discover here on this page (start a forum discussion specifically for this).

Thank you! I will journal and let you know.