Abstract:
Free-ranging spotted hyenas (Crocuta crocuta) are immobilised for a variety of purposes, including wildlife-human conflict
mitigation, research, and veterinary treatment. Combinations of tiletamine-zolazepam (Zoletil) and medetomidine are commonly
used for immobilisation of hyenas, however, recovery times are long.
In this descriptive study, a total of 20 adult or subadult free-ranging hyenas were immobilised near Skukuza in the Kruger National
Park using ketamine, butorphanol, and medetomidine. The goal of the study was to evaluate a suitable dose and measure
cardiorespiratory effects of this combination. The quality of induction and recovery were scored using an established scoring
system from 1 (excellent) to (poor).
Twelve of the 20 hyenas were given an induction score of 1 (excellent), five an induction score of 2 (good), and three an induction
score of 3 (fair). Of the animals with induction score = 1, the mean drug dose was 1.17 mg/kg ketamine, 0.25 mg/kg butorphanol
and 0.03 mg/kg medetomidine, and the mean induction time and time to handling 6:25 minutes and 9:46 minutes respectively.
The mean recovery time (from reversal to standing) was 10:16 min, which is shorter than what has been reported for tiletaminezolazepam-
based combinations in hyenas. Most hyenas were bradycardic (< 40 beats per minute) and the mean PaO2 69.5 mmHg.
Three hyenas, one with induction score = 2, and two with induction scores = 3 spontaneously recovered at 33, 44 and 56 minutes
post approach respectively. Regardless of induction time, all hyenas reached a level of surgical anaesthesia while immobilised.
Overall, ketamine-butorphanol-medetomidine (KBM) was effective in immobilising hyenas but induction times varied, and animals
were bradycardic during immobilisation.
