Managing HCM in cats — the most common cardiac disease in cats with variable welfare trajectories.
HCM welfare management is complex because the disease has highly variable progression. Many cats live for years with echocardiographically confirmed HCM without developing clinical signs. For these cats, regular monitoring and owner education constitute the welfare intervention — allowing early detection of progression to clinical disease before emergency presentation.
Congestive heart failure (pleural effusion causing respiratory distress) represents acute welfare impairment requiring emergency treatment. The distress of acute respiratory failure is severe — cats are in extremis, breathe with mouths open, and are profoundly frightened. Emergency thoracocentesis (draining fluid from the chest) provides rapid welfare relief.
Arterial thromboembolism (saddle thrombus, ATE) is the most devastating acute welfare event in HCM cats. The sudden loss of blood supply to the hindlimbs causes intense pain, paralysis, cold extremities, and vocalisation. The welfare decision of whether to attempt aggressive treatment or provide euthanasia is one of the most challenging in feline medicine. Even with treatment, recurrence is common and the underlying cardiac disease progresses.