Unclassified cardiomyopathy in a geriatric cat.

A 15-year-old, neutered male, domestic shorthair presented with dyspnea. Unclassified cardiomyopathy was diagnosed. Treatment resulted in a profound bradycardia, which was attributed to the administration of a beta-adrenergic blocker. The pathogenesis of unclassified cardiomyopathy is discussed and the side effects of beta-adrenergic blockers and angiotensin converting enzyme inhibitors are reviewed.