Ruptured left sinus of Valsalva aneurysm into the left atrium in a dog.

A dog with immune-mediated thrombocytopenia and a new heart murmur had an echocardiogram in 2016 and was found to have a suspected aorto-left atrial fistula. The echocardiogram findings remained relatively static from 2016 to 2022. This report highlights the use of cardiac-gated computed tomography angiography to allow further understanding of a complex anomaly in a patient with a ruptured sinus of Valsalva aneurysm causing a fistulous connection with the left atrium.