Euthanasia of rabbits by intravenous administration of ketamine

Six New Zealand White rabbits (5 females and 1 male) were anesthetized with a combination of xylazine (4.3 mg/kg of body weight) and ketamine (29.1 mg/kg) administered IM. The rabbits were then attached to instruments that continuously monitored blood pressure and electrocardiographic and electroencephalographic values. Each rabbit was then administered a lethal dose of ketamine (600 mg, IV). Within 90 seconds after injection of the ketamine, brain death developed and the heart rate and blood pressure decreased greatly. Circulatory activity persisted for a maximum of 240 seconds. This method of euthanasia did not result in histopathologic changes in tissue specimens evaluated. Although death occurred rapidly, extensive muscle contractions made euthanasia of rabbits with ketamine aesthetically unacceptable. Therefore, this method would not be a suitable means of euthanasia for routine use in rabbits.