Congenital Dilated Cardiomyopathy with Congestive Heart Failure in a Rhinoceros Hornbill (Buceros rhinoceros)
A 3-month-old rhinoceros hornbill (Buceros rhinoceros) presented for a distended coelom, wet cough, and hock-sitting stance. The animal had a history of poor growth and clumsy flight attempts compared to other offspring of the same age. On examination, the bird was found to have severe coelomic and pericardial effusion and an approximately 2-cm diameter, round, left lateral coelomic body wall hernia. Two-dimensional (2D) echocardiography revealed severe left atrial and ventricular dilation with moderate right atrial and ventricular dilation. The contractility of both ventricles was severely reduced with a fractional shorting of 16% and an ejection fraction of 34%. Color Doppler flow imaging showed severe mitral and tricuspid regurgitation associated with dilation of the annulus of the mitral and tricuspid valves, and severe pulmonary hypertension. The bird was treated with daily furosemide and supplemental oxygen therapy; however, it arrested 4 days after initial presentation. On postmortem examination, significant pericardial and coelomic effusions were present, consistent with right-sided congestive heart failure. The heart was thin walled, diffusely enlarged, and histologically unremarkable—indicative of a congenital lesion. Severe, chronic, passive congestion of the lungs was also present, consistent with left-sided congestive heart failure. Imaging and consultation with a veterinary cardiologist were integral to antemortem diagnosis of this first reported case of congenital dilated cardiomyopathy in a hornbill species.
Authors thank Phoenix Zoo’s animal care and veterinary technician staff for their assistance with this case.