The causes, classification and prevention of exertional rhabdomyolysis in racehorses

Abstract

Rhabdomyolysis is literally the disintegration of striated muscle fibres with the excretion of myoglobin in the urine. Exertional Rhabdomyolysis (ER) means that rhabdomyolysis is emanating or pertaining to exercise. This paper is important as ER effects a reported 6.7% of racehorses in training and so far there has been no definitive way to treat/prevent or classify the disease. From my literature review I found that sporadic ER is more than likely down to the training and management of racehorses, episodes can occur in horses when the trainers/jockey’s over exert their horses during work and episodes can also occur while the horse is dehydrated. I also ruled out certain theories such as Vit E and Selenium deficiencies and the build-up of lactic acid in the muscles were causing ER. Researching pedigrees of horses prone to ER, I was able to confirm that chronic ER (RER* and PSSM**) is a genetic trait inherited as an autosomal dominant. In RER the defect is found on the region of ECA16 chromosome and in PSSM type 1 on the gene GYS1.