The reversal of xylazine/ketamine immobilisation of fallow deer with yohimbine

Abstract

Fallow deer were immobilised using a combination of xylazine and ketamine. Adult males (n = 10) and adult females (n = 10) received 4 mg/kg of each drug intramuscularly. Juveniles (n = 11) received 2 mg/kg of each drug, intravenously. Times to recumbency were as follows: adult males 4.9 +/- 2.9 min, adult females 4.1 +/- 1.9 min, juveniles 2.3 +/- 1.1 min. After 30 min each deer received 0.2 mg/kg of yohimbine, or an equal volume of sterile diluent intravenously. Yohimbine substantially reduced the recovery times of treated deer. Adults males were releasable 7.2 +/- 4.3 min after yohimbine administration, whereas control males were not releasable until 165 +/- 18 min. Treated adult females were releasable after 6.6 +/- 4.3 min, while control females were not releasable until 84 +/- 29 min. Juveniles were releasable 2.1 +/- 0.8 min after administration of yohimbine but control juveniles were not releasable until 62 +/- 16 min. Xylazine/ketamine administration produced statistically significant changes in packed cell volume, total plasma protein, albumin, sodium, glucose, creatine phosphokinase and inorganic phosphate values after 30 min. Yohimbine administration had no effect on these changes.