Abstract
Among 544 cattle with congenital cardiovascular anomalies, five cases (0.9%) had the right aortic arch. They were five cases (0.1%) in a series of 5144 cattle necropsied at the Miyazaki University. Case 1 was complete heterotaxia and its heart and great vessels showed a mirror image of the normal. The other four had the situs solitus of the atria and abdominal organs. In case 2 the left subclavian artery originating from the brachiocephalic trunk, passed across the dorsal aspect of the esophagus over to the left side and formed an incomplete vascular ring. In cases 3 and 4 the left subclavian artery originating from the brachiocephalic trunk, crossed ventral to the trachea. In case 5 the aberrant left subclavian artery arose as the last branch of the aortic arch and passed across the dorsal surface of the esophagus. Moreover the left ductus arteriosus in this case connected the bifurcation of the pulmonary trunk with the distal part of the aortic arch, and a complete vascular ring was formed around the esophagus and trachea.
