Chemical restraint of African lions (Panthera leo) with medetomidine-ketamine.

Effects of a combination of medetomidine-ketamine as a chemical restraint and antagonistic effects of atipamezole on this combination were investigated in 5 lions. The medetomidine (47.6-58.4 micrograms/kg) and ketamine (1.9-5.7 mg/kg) combination provided complete immobilization with good analgesia and muscle relaxation in 4 lions, while one lioness was poorly sedated by medetomidine, and additional injections of medetomidine and ketamine were required. The duration of anesthesia seemed to be much longer than one hour in 4 of the lions. Atipamezole, at four times the preceding dose of medetomidine, provided a smooth recovery and animals were able to stand up 17-61 min after its injection. Side effects were limited to vomiting after walking in 3 of 5 lions.