MSD Manual

Please confirm that you are a health care professional

honeypot link
Professional Version

Persistent Right Aortic Arch in Animals


Sandra P. Tou

, DVM, DACVIM-Cardiology, DACVIM-SAIM, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University

Reviewed/Revised Jan 2020 | Modified Oct 2022

Persistent right aortic arch is the most common vascular ring anomaly in dogs (German Shepherds in particular) and has also been reported in cattle, horses, and cats. The right aortic arch fails to regress normally, resulting in entrapment of the esophagus and trachea at the level of the heart base. The structures are encircled by the persistent arch on the right, by the ligamentum arteriosum on the left and dorsally, and by the base of the heart ventrally. The esophagus is typically compressed, leading to esophageal dilation cranial to the heart base and the most common clinical sign of regurgitation (often noted at weaning). Aspiration pneumonia is common in affected animals. Surgery is recommended to transect the ligamentum arteriosum to free the esophagus from entrapment. Radiographically, right-ward deviation of the trachea on dorsoventral or ventrodorsal view is highly sensitive and specific for the diagnosis of persistent right aortic arch. CT can confirm the diagnosis before surgery and assist surgical planning.

quiz link

Test your knowledge

Take a Quiz!