Massive haemorrhage associated with inadvertent incision of a suspected carotid artery pseudoaneurysm in a cat.

A 12-year-old, castrated male, domestic long-haired cat experienced massive haemorrhage associated with an incision of a swelling on the neck 2 weeks after right-sided ventral bulla osteotomy. Emergent control of haemorrhage was gained through unilateral carotid artery ligation. Cardiopulmonary resuscitation was provided in conjunction with massive blood transfusion. The cat made an unremarkable recovery. Carotid artery pseudoaneurysm due to surgical disruption of the carotid artery during ventral bulla osteotomy, specifically through the use of self-retaining retractors, was suspected. This case highlights the development of pseudoaneurysm as a potential complication of head and neck surgery, and additionally describes a case of massive transfusion in a cat.