Hypertrophic cardiomyopathy (HCM) is the most common cardiac disease in cats, often detected incidentally, and carries welfare implications from sudden cardiac death and congestive heart failure.
HCM presents a welfare challenge because the condition is often silent until catastrophic events — either sudden death from arrhythmia or the acute severe welfare emergency of aortic thromboembolism. ATE causes sudden acute pain and distress as blood supply to the hindlimbs is cut off — affected cats cry out, drag paralysed hindlimbs, and are in extreme distress. The decision whether to treat or euthanase an ATE cat is complex and acutely welfare-relevant. Screening echocardiography for predisposed breeds and regular screening of all cats over age 7 identifies HCM before catastrophic events, allowing risk-stratified management. Clopidogrel prophylaxis in high-risk HCM cats reduces the welfare burden of ATE events.