TILETAMINE-ZOLAZEPAM ANESTHESIA IN NORTH-AMERICAN RIVER OTTERS (LUTRA-CANADENSIS) AND ITS PARTIAL ANTAGONISM WITH FLUMAZENIL

North American river otters (Lutra canadensis) were anesthetized with tiletamine-zolazepam or tiletamine-zolazepam-flumazenil combinations i n cooperation with the North Carolina Wildlife Resources Commission Ot ter Restoration Project for evaluation of physiologic changes during a nesthesia. Sixteen otters received tiletamine-zolazepam (4 mg/kg combi ned, i.m.) in 1994. Induction and recovery times were recorded and phy siologic data (heart rate and rhythm, respiratory rate, rectal tempera ture, relative oxyhemoglobin saturation, and mean arterial blood press ure) were collected at 5-min intervals. Respiratory depression develop ed initially in all otters, and median relative oxyhemoglobin saturati on remained below 90% for the first 15 min of anesthesia. Anesthetic i nduction with tiletamine-zolazepam was rapid and smooth, but recovery was prolonged (median = 89 min) and characterized by persistent head m otion. In 1995, flumazenil was evaluated as a partial antagonist for t iletamine-zolazepam anesthesia in otters. Sixteen otters were anesthet ized with tiletamine-zolazepam (4 mg/kg combined, i.m.) and given flum azenil (1 mg per 25 mg of zolazepam) after 20 min. Flumazenil markedly shortened recovery time in all otters anesthetized with tiletamine-zo lazepam (median = 65 min) with no adverse effects.