Tricuspid valve dysplasia and a patent foramen ovale resulting in severe tricuspid regurgitation and right-heart dilation in a Red Angus calf.

A two-month-old Red Angus heifer calf presented to the University of Wisconsin Veterinary Care for evaluation of suspected severe bronchopneumonia. Pertinent physical exam findings included tachycardia, tachypnea, dyspnea with a significant abdominal component, and cyanotic mucous membranes. On thoracic auscultation, wheezes were present bilaterally, as well as a grade 2/6 right apical systolic murmur. Thoracic radiographs revealed cardiomegaly, most severely affecting the right side. Echocardiography showed tricuspid valve dysplasia, resulting in severe tricuspid regurgitation and right-heart dilation, as well as a patent foramen ovale. A postmortem examination confirmed the presence of the aforementioned cardiac abnormalities and revealed only mild pulmonary changes. This case report is the first to describe tricuspid dysplasia in the absence of multiple, complex congenital cardiac abnormalities in a calf, and it highlights the value of echocardiography for an antemortem diagnosis.