Exertional rhabdomyolysis in horses: what to know

Exertional rhabdomyolysis in horses is exercise-related muscle injury that needs prompt veterinary assessment. It can cause firm or painful muscles, sweating, stiffness, reluctance to move, and dark urine. The episode may follow strenuous work, a sudden return to exercise, stress, or an individual tendency to muscle episodes.

During an episode, muscle cells are damaged and release their contents into the bloodstream. The hindquarters are often noticeably tight, and a horse may take short steps or resist being led. Signs can begin during work or soon afterward. A veterinarian may examine movement and muscles and use blood and urine tests to assess muscle injury and kidney effects. Similar signs can have other causes, so a diagnosis should not be made from appearance alone.

Stop exercise and keep the horse calm. Do not force walking, loading, stretching, or further work if movement is painful. Offer water if the horse can drink normally, keep the environment quiet, and contact a veterinarian promptly. Note the work performed, recent rest or diet changes, medications, sweating, urine colour, and when signs began. Follow the veterinary plan for fluids, pain control, rest, and a gradual return to activity.

Seek urgent veterinary help for severe stiffness, collapse, inability to stand or walk, repeated sweating, marked distress, very dark urine, reduced urination, or worsening weakness. These signs can indicate substantial muscle injury or complications involving hydration and kidney function. A horse that seems better still needs professional advice before exercise resumes.

Ask what tests are needed, whether fluids or pain relief are appropriate, how much movement is safe, which feeding or training changes may reduce future episodes, and what signs should trigger an immediate call.