A five-year-old domestic shorthair cat underwent general anaesthesia and tooth extractions. Immediately after use of a high-speed, air-driven, water-cooled dental drill, the cat suffered cardiac arrest and attempted resuscitation was unsuccessful. Post-mortem radiographs showed air in the vena cava, right atrium, right auricle and right ventricle, hepatic and renal veins. These findings were confirmed at post-mortem examination. The cause of death was massive air embolism. There are reports of fatal venous air embolism in the human literature from the use of high-speed, air-driven, water-cooled dental drills. In this case, we believe that the air jet from the cooling system provided an enormous pressure gradient allowing air entry through an alveolar bone fracture or the inflamed gingival tissues. This is the first report of fatal venous air embolism associated with the use of a high-speed dental drill in the veterinary literature.