A congenital shunt between the right costocervical artery, left coronary artery, and left pulmonary artery in a dog.

A one-year-old neutered male Kooikerhondje dog, weighing 12 kg, was referred for evaluation of a heart murmur without clinical signs and mosaic blood flow within the main pulmonary artery detected by transthoracic echocardiography. On day 0, transthoracic echocardiography revealed left heart enlargement, continuous mosaic flow within the main pulmonary artery, and a shunt vessel entering the left pulmonary artery. Electrocardiography (ECG)-gated non-helical computed tomography angiography (CTA) using a 320-row multidetector computed tomography scanner demonstrated two anomalous vessels that converged to form a common trunk draining into the left pulmonary artery: one arising from the right costocervical artery, coursing tortuously through the thoracic cavity, and entering the origin of the left pulmonary artery (right costocervical artery-left pulmonary artery shunt) and another arising from the left coronary artery and entering the origin of the left pulmonary artery (left coronary artery-left pulmonary artery shunt). On day 47, both shunt vessels were completely ligated at their entry points into the left pulmonary artery via thoracotomy, resulting in the disappearance of shunt flow. On day 234, ECG-gated CTA confirmed the complete disappearance of both shunts and the absence of any additional abnormal vessels. To the authors' knowledge, this is the first report of concurrent right costocervical artery-left pulmonary artery and left coronary artery-left pulmonary artery shunts in a dog, diagnosed using ECG-gated CTA and successfully treated surgically.