Review of exertional rhabdomyolysis and a case in a rhesus monkey (Macaca mulatta).

This is the first confirmed report of exertional rhabdomyolysis in a non-human primate. The monkey was singly housed and presented with anorexia and reluctance to move. There was no external evidence of trauma. Clinicopathologic findings included mild azotemia, marked elevation in serum creatine phosphokinase (CPK), alanine aminotransferase, aspartate aminotransferase, and myoglobinuria. Two days post-incident, the peripheral skeletal muscle had marked multifocal myonecrosis and fibrillar disruption without an inflammatory reaction. Treatment included diuresis and pain relief, and urinary output was monitored. The monkey recovered over the next two weeks. The major significance of skeletal muscle damage is the potential of released myoglobin to cause acute renal failure in the presence of other co-factors such as hypovolemia, acidosis, or ischemia. CPK levels can be highly variable and are inconsistent with the degree of muscle damage; however, CPK is thought to be the most sensitive enzyme marker for muscle necrosis. Because of the potential life-threatening sequelae, exertional rhabdomyolysis should be included as a differential diagnosis when similar clinical and pathological signs are observed.