Surgical correction of ventricular septal defect in a cat.

A two-year-old intact male British shorthair cat, weighing 4.6 kg, was referred for surgical correction of a ventricular septal defect (VSD). The cat was treated with pimobendan, amlodipine, furosemide, and clopidogrel for tachypnea, and no other clinical signs of cardiac disease were observed. Physical examination revealed heart murmurs. Radiographic and echocardiographic evaluations indicated generalized cardiomegaly and left atrial enlargement. Two-dimensional echocardiography revealed a large left-to-right shunt through a 5.8-mm perimembranous VSD with a septal aneurysm. The pulmonary-to-systemic blood flow ratio was 3.3, indicating a substantial volume overload. Surgical correction was performed via a right ventricular outflow tract incision under cardiopulmonary bypass using an 8-mm expanded polytetrafluoroethylene patch to close the VSD. Postoperatively, the cat had sporadic premature ventricular contractions but recovered without major complications. At one year postoperatively, the cat showed improved activity levels and no residual shunt flow and required no medication. This report demonstrates the feasibility of patch closure for membranous VSDs in cats through a right ventricular outflow tract incision and highlights the need for further studies to assess its effectiveness.