Vascular ring anomaly (VRA) is a congenital malformation of the great vessels that result in regurgitation and recurrent aspiration pneumonia. Although there are many types of vascular ring anomalies, persistent right aortic arch (PRAA) accounts for more than 95% of all cases. Diagnosis of VRA usually occurs soon after weaning, but occasionally the diagnosis is delayed resulting in the potential development of additional medical problems. In this case report, we discuss a dog with chronic regurgitation and poor weight gain caused by PRAA that was not diagnosed until nearly one year of age. The types of vascular ring anomalies, the embryologic development of the condition, and the associated medical problems are reviewed.