## Overview Gluteal myopathy or tying-up is exertional rhabdomyolysis affecting the hindquarter muscles. During or after exercise the muscles become firm and painful, the stride shortens, and the horse may sweat excessively. Myoglobinuria (dark urine) and elevated muscle enzymes confirm muscle damage. ## Causes Exercise beyond conditioning, electrolyte imbalance, or underlying genetic myopathies (polysaccharide storage myopathy, recurrent exertional rhabdomyolysis). ## Diagnosis Clinical signs plus markedly elevated creatine kinase and aspartate aminotransferase. Urinalysis for myoglobin. Genetic testing when recurrent. ## Treatment Immediate rest, fluids, pain control, and prevention of kidney damage from myoglobin. Long-term management addresses diet and exercise for underlying myopathies. ## Recovery and Prognosis Good for single episodes with prompt care. Recurrent cases need ongoing management. ## Prevention Gradual conditioning, appropriate diet, and electrolyte balance.
firm painful hindquarters during or after exercise; shortened stride; sweating; dark urine; elevated muscle enzymes
## Overview Gluteal myopathy or tying-up is exertional rhabdomyolysis affecting the hindquarter muscles. During or after exercise the muscles become firm and painful, the stride shortens, and the horse may sweat excessively. Myoglobinuria (dark urine) and elevated muscle enzymes confirm muscle damage. ## Causes Exercise beyond conditioning, electrolyte imbalance, or underlying genetic myopathies (polysaccharide storage myopathy, recurrent exertional rhabdomyolysis). ## Diagnosis Clinical signs plus markedly elevated creatine kinase and aspartate aminotransferase. Urinalysis for myoglobin. Genetic testing when recurrent. ## Treatment Immediate rest, fluids, pain control, and prevention of kidney damage from myoglobin. Long-term management addresses diet and exercise for underlying myopathies. ## Recovery and Prognosis Good for single episodes with prompt care. Recurrent cases need ongoing management. ## Prevention Gradual conditioning, appropriate diet, and electrolyte balance.
firm painful hindquarters during or after exercise; shortened stride; sweating; dark urine; elevated muscle enzymes