MYHM is a muscle disease in horses, presenting as immune-mediated myositis or non-exertional rhabdomyolysis. Detected through the MYH1 gene, it causes stiffness, muscle weakness, and rapid loss of muscle mass. Environmental triggers like infection or vaccination can activate the disease, especially in younger or older horses. Testing helps breeders avoid producing affected horses and guides vaccination decisions, contributing to better management strategies.
