Prenatal Ultrasonographic Detection of Intracardiac Thrombi in Canine Fetuses With Congenital Heart Defects

A 5-year-old pregnant Newfoundland bitch was evaluated by monitoring fetal viability. Transabdominal ultrasonography of the reproductive tract revealed a homogeneous and hyperechoic mass within the right ventricle associated with abnormal tricuspid valve in a fetus. A similar mass was also visualized in the right atrium of another fetus. The bitch delivered 11 puppies, four of which died after parturition. Necropsy showed tricuspid stenosis in all puppies, with concomitant pulmonary stenosis in one of them. Moreover, an intraventricular thrombus and an interatrial thrombus were each revealed in two puppies. This case series demonstrates the feasibility of prenatal ultrasonographic detection of intracardiac thrombi in canine fetuses and highlights its potential value for early diagnosis of congenital heart defects.