Severe oesophageal constriction due to an aberrant right subclavian artery with Kommerell’s diverticulum in a cat

CASE SUMMARY: A 6-month-old female cat with a history of chronic regurgitation presented with weight loss. CT angiography (CTA) showed severe constriction of the oesophagus due to an aberrant right subclavian artery and Kommerell’s diverticulum. The cat was surgically treated and remained clinically normal. More than 1 year after surgery, the general condition of the cat was stable and body weight had increased. RELEVANCE AND NOVEL INFORMATION: This case report describes the clinical findings and surgical management of a cat diagnosed with severe oesophageal constriction caused by an aberrant right subclavian artery with Kommerell’s diverticulum (markedly dilated origin of the aberrant right subclavian artery), which are rare vascular anomalies in veterinary medicine and specifically in cats. The Kommerell’s diverticulum compressed the oesophagus and contributed to the severe oesophageal constriction in this case. Preoperative CTA was useful in the diagnosis and treatment planning.