COMPARISON OF ANESTHETIC AND CARDIORESPIRATORY EFFECTS OF TILETAMINE-ZOLAZEPAM-XYLAZINE AND TILETAMINE-ZOLAZEPAM-XYLAZINE-BUTORPHANOL IN FERRETS

Nine ferrets were used in a crossover study to determine the anestheti c effects of intramuscular (IM) administration of a low dose of tileta mine-zolazepam (1.5 mg/kg body weight)-xylazine (1.5 mg/kg body weight ); a high dose of tiletamine-zolazepam (3 mg/kg body weight)-xylazine (3 mg/kg body weight), and tiletamine-zolazepam (1.5 mg/kg body weight )-xylazine (1.5 mg/kg body weight)-butorphanol (0.2 mg/kg body weight) . All ferrets became laterally recumbent within two minutes following the administration of each drug combination. The tiletamine-zolazepam- xylazine-butorphanol combination induced significantly longer (p less than 0.05) durations of fail clamp analgesia (mean+/-standard deviatio n [SD], 90.0+/-17.1 min versus 17.8+/-15.8 min and 41.9+/-26.3 min) an d endotracheal intubation (mean+/-SD, 84.8+/-21.7 min versus 5.2+/-10. 3 min and 26.3+/-29.8 min) than the low-dose tiletamine-zolazepam-xyla zine and high-dose tiletamine-zolazepam-xylazine combinations, respect ively. Heart rates and the times from dorsal recumbency to standing we re not significantly different among the three treatment groups. Howev er, systolic blood pressure was significantly lower in the tiletamine- zolazepam-xylazine-butorphanol group. Ventilatory function was more de pressed in the tiletamine-zolazepam-xylazine-butorphanol group than in the low-dose tiletamine-zolazepam-xylazine and high-dose tiletamine-z olazepam-xylazine groups. A short period of hypoxia was observed in th e tiletamine-zolazepam-xylazine-butorphanol-treated ferrets. Tiletamin e-zolazepam-xylazine-butorphanol was found to be the best of the three combinations evaluated in these ferrets. The addition of butorphanol to the low-dose tiletamine-zolazepam-xylazine combination greatly enha nced the duration of analgesia, endotracheal intubation, and dorsal re cumbency. However, since hypoxemia occurred during the tiletamine-zola zepam-xylazine-butorphanol anesthesia, oxygen (O-2) insufflation is re commended. Doubling the dose of the low-dose tiletamine-zolazepam-xyla zine increased the duration of analgesia and endotracheal intubation w ithout prolonging the recovery when compared to the low-dose tiletamin e-zolazepam-xylazine group.