Several inherited muscle disorders cause significant pain and welfare impacts in horses. Genetic testing and appropriate management reduce suffering for affected animals.
Inherited muscle disorders in horses cause significant welfare impacts through episodes of acute pain, muscle damage, and in severe cases, complete inability to move. PSSM episodes cause visible distress — affected horses show sweating, reluctance to move, muscle trembling, and in severe cases, recumbency from which they cannot rise. The genetic origin of these conditions makes breeding decisions a welfare responsibility: continuing to breed HYPP-positive animals, or breeding PSSM-positive animals without dietary management protocols, perpetuates preventable suffering. Management — primarily through appropriate diet and exercise programmes — can significantly reduce episode frequency for both conditions. The welfare cost of poorly managed or unrecognised muscle disorders accumulates over years of affected horses working through pain.