Nutritional Support for Rhabdomyolysis

Abstract

ying-up is a horseman’s descriptive term for exertional rhabdomyolysis (ER). Both terms describe the results of a number of specific muscle pathologies that appear to have a single cause. Recent studies, however, show that there are a number of specific causes of ER, and that information helps to understand why prevention and treatment has been elusive over the years. Many years ago when the condition was first described in draft horses, it was thought that diet had a lot to do with the condition. It occurred in work horses generally on Monday mornings—thus the term “Monday morning disease” was coined. A nutritional prevention plan was devised that was quite successful in many cases. What happened was that horses were worked hard six days a week and kept in their stalls on Sunday (to rest). The same amount of grain was fed Sunday as the rest of the week. Often this grain contained a large amount of molasses. Looking back on the situation, once muscle physiology was better understood, it appeared that the muscle cells were being overloaded with glycogen with no way to utilize it. Cutting the Sunday grain feeding usually helped alleviate the problem. Today we see a different type of ER with the expansion of horse racing and other intense pleasure horse activities. At the recent ACVIM Forum in Charlotte, North Carolina, Dr Stephanie Valberg provided some useful nutritional advice on ER under the catchy title “untying the knots through nutrition.” She emphasized that despite similarities of clinical signs, pathogenesis can vary from case to case. She described the typical ER and other types such as recurrent exertional rhabdomyolysis, sporadic ER, chronic ER, and polysaccharide storage myopathy.