Exertional rhabdomyolysis or tying-up causes severe muscle pain and distress in horses during or after exercise, and understanding the underlying causes enables better management and prevention.
Tying-up represents a welfare emergency when it occurs, as affected horses experience severe and acute muscle pain that immobilizes them and causes extreme distress. The sweating, trembling, and rigid posture of a horse in a tying-up episode indicate an animal in significant pain. Immediate welfare response requires stopping exercise and providing veterinary care to manage pain and prevent renal damage from myoglobin released by muscle breakdown. For horses with recurrent episodes due to genetic muscle disorders, the welfare challenge is ongoing management to prevent the trigger conditions for recurrence. Understanding the specific genetic form affecting the horse guides dietary and exercise management that can dramatically reduce episode frequency. Horses managed appropriately for their genetic condition can have good welfare and productive working lives.