Aberrant Right Subclavian Artery Incidentally Detected in Eight Adult Dogs: CT Findings and Possible Association with Intermittent Regurgitation

An aberrant right subclavian artery (ARSA) is an uncommon vascular anomaly that may cause oesophageal compression and clinical signs such as regurgitation. This exploratory case series describes the computed tomography (CT) findings of isolated ARSA in eight adult dogs (aged 3–13 years) examined for unrelated conditions. Contrast-enhanced CT images were evaluated for the origin and course of the aberrant artery, its relationship with the oesophagus and trachea, and evidence of oesophageal compression or secondary changes. In all dogs, the right subclavian artery originated directly from the aortic arch and followed a course from left to right, passing dorsal to the oesophagus and trachea, producing mild focal oesophageal compression. No oesophageal dilation or abnormal intraluminal accumulation of gas or fluid was identified. Following CT identification of ARSA, targeted questioning of the owners revealed a history of rare or intermittent regurgitation in six of the eight dogs (75%). Although a causal relationship between ARSA and regurgitation could not be established, these findings suggest that isolated ARSA may be associated with subtle oesophageal compression in adult dogs. The incidental identification of this vascular anomaly on CT may be relevant when evaluating dogs with intermittent regurgitation.