MYOCARDIAL-INFARCTION IN DOGS AND CATS - 37 CASES (1985-1994)

Objective-To determine the incidence of acute and subacute myocardial infarction on postmortem examination, identify associated diseases, an d evaluate clinical or diagnostic indicators of myocardial infarction in dogs and cats. Design-Retrospective study. Animals-32 dogs and 5 ca ts, Procedure-Records from the necropsy service from December 1985 thr ough August 1994 were searched for dogs and cats in which acute or sub acute myocardial infarction was diagnosed on postmortem examination. C linical records were reviewed for signalment, initial owner complaint, medical history, results of physical examination, electrocardiography , radiography, echocardiography, CBC, serum chemistry analysis, urinal ysis, and coagulation profile as well as clinical course, outcome, nec ropsy findings, and results of histologic evaluation. Results-Initial owner complaints and physical examination findings were consistent wit h associated diseases. Electrocardiographic abnormalities in dogs incl uded ventricular tachycardia (16%), atrial fibrillation (9%), and prem ature ventricular contractions (6.5%). Premature ventricular contracti ons were noticed in 2 cats. Echocardiography revealed dilated, poorly contractile hearts (n = 3) and thickened mitral valves (2) in dogs, an d ventricular hypertrophy (3) in cats. Ninety-seven percent of dogs ha d infarction of the left ventricle as well as other other portions of the heart. Infarctions in cats were found in all parts of the myocardi um including the right ventricle (n = 3), left ventricle (3), and inte rventricular septum (1). Clinical Implications-Myocardial infarction i s rare in dogs and cats. It is associated with a number of common dise ases and may contribute to morbidity and mortality in those dogs and c ats that are critically ill.