IMMOBILIZATION OF BLACK BEARS (URSUS-AMERICANUS) WITH ORALLY-ADMINISTERED CARFENTANIL CITRATE

Ten black bears (Ursus americanus) were immobilized with orally admini stered carfentanil citrate. The total carfentanil dose was mixed with 5 to 20 ml honey and given incrementally to captive bears. The bears r anged in weight from 80 (estimated) to 233 kg. Total carfentanil doses ranged from 0.7 to 3.0 mg, resulting in dosages of 6.8 to 18.8 mu g c arfentanil/kg. Mean (+/-SD) times from estimated 80% mixture consumpti on to sternal recumbency, and first safe human contact were 7.7 +/- 2. 3 min and 19.7 +/- 5.6 min, respectively. Undesired side effects of im mobilization were muscle rigidity, bradypnea, and oxygen desaturation. All bears received diazepam to alleviate muscle rigidity and were ins ufflated with oxygen during immobilization. Nine immobilizations were considered satisfactory or good. The bear receiving 6.8 mu g carfentan il/kg, the lowest dosage used, was very excited during induction and r equired intravenous (IV) ketamine to permit safe examination. Immobili zation was reversed with 100 mg naltrexone/mg carfentanil administered (75% subcutaneous, 25% IV). Bears recovered to full mobility in 6.3 /- 1.9 min. Five bears vomited post-recovery but no episodes of re-nar cotization were observed.