The brachiocephalic trunk and the left subclavian artery originate from the aortic arch, and both supply blood to the head, neck, and thoracic limbs. Anatomical variations, such as an aberrant right subclavian artery, are congenital conditions rarely observed in dogs, Thus, the objective of the present report was to describe a case of aberrant right subclavian artery in a 9-year-old Dalmatian. However, this anomaly was a finding in which the patient was asymptomatic during its 9 years of life and only at this age did he exhibit signs including sialorrhea, vomiting, hyporexia, and noisy deglutition. Blood count, biochemical profile, and thoracic radiography led to a diagnosis of megaesophagus and aspiration pneumonia. Despite the recommended treatment, the patient did not respond well; as such, the owner elected to euthanize the animal. On necropsy, the right subclavian artery originated directly from the aortic arch, followed a route from left to right dorsally to the esophagus, and then formed an impression of the vascular path over the muscular wall of the esophagus. The esophagus, in turn, exhibited a flaccid wall and dilation in the caudal portion to the vascular path made by the ectopic position of the right subclavian artery.
vascular anomaly; aortic arch; esophageal dilation; canine