The most common Esophageal Vascular Ring Anomaly seen in dogs in the Persistent Right Aortic Arch. The aortic arch develops on the right side rather than its normal side on the left. This drags the ligamentous arteriosum across the esophagus causing a mid-thoracic obstruction. The esophagus dilates in front of the obstruction (heart). The longer this situation persists the larger the esophagus becomes.

Esophageal regurgitation with pulmonary aspiration is a significant complication. The earlier the condition is treated (surgical relief of the esophageal obstruction), the better the prognosis for clinical resolution of regurgitation issues. The esophagus will never return to normal as it is permanently changed.