This acute exertional myopathy of racing Greyhounds and working dogs is characterized by muscle ischemia secondary to exercise or excitement. Avascularity and lactic acidosis cause muscular lysis, myoglobin release, and a nephropathy.
Clinical signs include muscle pain and swelling 24–72 hours after racing. Severe cases are characterized by stiffness, hyperpnea, collapse, myoglobinemia, and acute renal failure. Urinalysis reveals myoglobinuria; serum potassium, phosphorus, and muscle enzymes are increased. Treatment includes supportive care such as IV fluids, bicarbonate, body cooling, rest, and muscle relaxants (eg, diazepam). Prognosis depends on severity. (Also see Exertional Myopathies in Horses Exertional Myopathies in Horses Exertional myopathy in horses is a syndrome of muscle fatigue, pain, or cramping associated with exercise. Less common exertional myopathies that cause exercise intolerance without muscle necrosis... read more 
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Also see pet health content regarding exertional myopathy in dogs Exertional Myopathy (Rhabdomyolysis) Myopathies are diseases that primarily cause damage to muscles or muscle tissues. They may be present at birth or occur due to nutritional imbalances, injury, metabolic disturbances, cancer... read more .
