A 3-month-old male, Cocker Spaniel with persistent regurgitation immediately after weaning and stunted growth was referred. Radiographic findings on the lateral view include ventral deviation of the thoracic trachea caused by draping of the dilated esophagus and a distinct interface of the dorsal wall of the esophagus silhouetting with the cranial thoracic hypaxial muscles. On the ventrodorsal view, the cranial mediastinum was widened with soft tissue opacity. The trachea was deviated to the right. In an esophagogram, the segmental dilation of the esophagus with constriction of the lumen just cranial to the heart base was identified. In a fluoroscopic examination, the contrast medium was massively accumulated in the cranial portion of the constricted esophagus. At surgery, it was confirmed that the esophageal tract was constricted at the cranial to the base of the heart by aberrant right subclavian artery. It was ligated and divided surgically. Current state of the referred is maintained normal condition from the surgical repair.