Zolazepam-tiletamine-medetomidine versus butorphanol-azaperone-medetomidine for the immobilisation of captive leopards (Panthera pardus)

Abstract

Objective To compare the immobilisation time and cardiopulmonary effects of zolazepam-tiletamine-medetomidine (ZM) and butorphanol-azaperone-medetomidine (BAM) in captive leopards (Panthera pardus).

Study design Prospective, clinical study

Materials and Methods 17 adult, captive leopards were immobilised by remote injection of either a combination of zolazepam-tiletamine (1.5 mg kg-1) and medetomidine (0.04 mg kg-1) (ZM, n = 10) or a combination of butorphanol (0.3 mg kg-1), azaperone (0.12 mg kg-1) and medetomidine (0.12 mg kg-1) (BAM, n = 7). Time to safe approach, judged by absent responses to an ear flick and tail tug, was recorded as the immobilisation time. Following immobilisation, cardiopulmonary parameters were recorded and two arterial blood gas samples analysed. After 40 minutes, anaesthesia was reversed using atipamezole (0.2 mg kg-1) for group ZM or atipamezole (0.6 mg kg-1) and naltrexone (0.3 mg kg-1) for group BAM. Recovery time was recorded as time from injection of reversal agent to head up. Data is reported as mean ± standard deviation and compared using a general linear mixed model (p < 0.05).

Results For ZM, doses administered were zolazepam-tiletamine 1.3 ± 0.6 mg kg-1 and medetomidine 0.04 ± 0.018 mg kg-1 while those for BAM were butorphanol 0.33 ± 0.05 mg kg-1, azaperone 0.13 ± 0.02 mg kg-1 and medetomidine 0.13 ± 0.02 mg kg-1. Immobilisation time was significantly faster for BAM (5.8 ± 1.1 minutes) than for ZM (11.8 ± 3.3 minutes, p = 0.008). Both treatments resulted in hypertension, with mean arterial blood pressure of 154 ± 46 mmHg with ZM and 137 ± 12 mmHg with BAM. BAM resulted in clinically significant hypoxaemia (arterial oxygen tension 52.8 ± 4.4 mmHg), while arterial oxygen tension was higher with ZM (72.6 ± 8.0 mmHg, p = 0.027). Arterial carbon dioxide tension was lower with ZM (26.4 ± 2.9 mmHg) than BAM (44.8 ± 3.9 mmHg, p < 0.001). Recovery time was not different between treatments (p = 0.604).

Conclusion Both combinations provided acceptable immobilisation for field use. Supplementation with oxygen is recommended, especially when using BAM.