Use of orally administered carfentanil prior to isoflurane-induced anesthesia in a Kodiak brown bear.

A captive 590-kg (1,298-lb) 22-year-old castrated male Kodiak brown bear was evaluated because of a soft tissue mass in the right carpal and antebrachial regions. General anesthesia was deemed necessary on 3 occasions for various procedures including radiographic evaluation and biopsy, excision, and radiation treatment. The bear was given carfentanil orally to induce sedation, followed by i.m. administration of tiletamine-zolazepam (on 1 occasion) and atropine. Anesthesia was maintained by administration of isoflurane in oxygen. After each procedure, effects of carfentanil were reversed by administration of naltrexone. Although there was some variability, blood pressure, nasal temperature, heart rate, respiratory rate, oxygen saturation, PO2, and PCO2 remained within a clinically acceptable ranges.