Dilated cardiomyopathy (DCM) is a progressive heart disease causing heart enlargement and failure in dogs, particularly affecting giant and large breeds with significant welfare implications.
DCM causes progressive cardiovascular insufficiency — affected dogs experience exercise intolerance, breathlessness, and weakness as the disease advances. Congestive heart failure causes fluid accumulation in the lungs, resulting in distressing dyspnea. Sudden death from arrhythmia occurs without warning. The occult phase is particularly concerning from a welfare standpoint because dogs suffer physiological compromise without visible signs that prompt owner action. Management medications require careful monitoring and owners who can administer multiple daily drugs. End-stage DCM involves severe respiratory distress that must be managed compassionately. Breed-specific prevalence makes genetic screening programs ethically important to reduce the number of dogs born at high risk.