A clinical case of a large ventricular septal defect with an atrial septal defect and a double-chambered right ventricle in a Holstein calf

Abstract

A 24-day-old Holstein male calf was presented with tachypnea and poor growth. At the initial presentation, tachypnea and exercise intolerance were confirmed, and systolic murmurs were noted at right apical site auscultation and confirmed by phonocardiogram. Echocardiography revealed a large ventricular septal defect （VSD） with an extremely short interventricular septum. An abnormal structure extending from the right ventricular free wall was found inside of the right ventricular. Necropsy revealed an atrial septal defect （ASD） in addition to a large perimembranous defect extending into the inlet septum of the defective ventricular septum （5.5 cm in diameter）. In the right ventricle, an enlarged abnormal muscle band was found, and it was forming a wall-like structure dividing the right ventricle into two spaces. The tendons of the tricuspid valve showed abnormal attachment due to the malformed right ventricle. This was a very rare case of concurrent VSD, ASD and a double-chambered right ventricle.