Left coronary artery to main pulmonary artery fistula in a dog

A vascular communication between the left coronary artery and the main pulmonary artery (coronary fistula) was diagnosed as an incidental finding in a 3-year-old female Tatran hound by echocardiography as part of preanesthetic evaluation. The history, clinical examination, and diagnostic imaging did not reveal evidence of trauma or endocarditis which could have led to this condition. Transthoracic echocardiography revealed dilation of the left coronary sinus secondary to an abnormal vessel shunting blood into the main pulmonary artery. Computed tomography confirmed this diagnosis. Coronary artery fistula is a very rare finding in human and animals. According to the authors, this is the first clinical case of a congenital fistula between the left coronary artery and the main pulmonary artery in a dog.