Challenging anaesthetic management of captive reindeer (Rangifer tarandus): Report of 4 cases.

INTRODUCTION: Four captive reindeer underwent anaesthesia to allow dehorning or drainage of lymph nodes abscessation. Premedication was based on xylazine (dose range: 0.075- 0.5 mg/kg, IM or IV), with or without ketamine (dose range: 1-2 mg/kg, IM or IV), all of which failed to produce effective sedation without side effects. During anaesthesia, 2 reindeer experienced severe hypoxaemia and hypoventilation. Recovery was smooth in 3 out 4 animals, but delayed in one reindeer sedated with 0.5 mg/kg of xylazine IV; this patient required repeated atipamezole administrations (0.01 mg/kg IM given 3 times) to regain normal locomotion. Anaesthesia of reindeer is challenging and useful dose ranges for safe and effective anaesthesia are mostly unknown.