Delayed Clinical Onset of Congenital Heart Disease in a Geriatric Macaw (<i>Ara ararauna</i>).

An approximately 33-year-old male blue and gold macaw (<i>Ara ararauna</i>) was presented for postmortem examination after dying without premonitory signs at the owner's home. The bird had a recent history of a grade II/VI left-sided systolic murmur, feather-destructive behavior, was overweight, and had bilateral cataracts. Gross and microscopic postmortem examinations revealed a subaortic interventricular septal saccular defect most compatible with a diverticulum intimately associated with a multifocally fibrotic right coronary aortic semilunar cusp, and its distended sinus. The resulting congestive heart disease was morphologically characterized by concentric myocardial hypertrophy of the left ventricle and cardiogenic pulmonary edema. Reports of cardiac congenital disease in birds include ventricular septal defects, congenital aneurysm, persistent truncus arteriosus, aortic hypoplasia, duplicitas cordis, multiplicatis cordis, and ectopia cordis. To the best of the authors' knowledge, this is the first documentation of a subaortic interventricular septal saccular defect in an avian species. This case adds to the knowledge of cardiovascular disease and raises awareness of delayed-onset clinical disease linked with congenital heart anomalies in birds.