A comparison of immobilisation quality and cardiorespiratory effects of etorphine-azaperone versus etorphine-midazolam combinations in blesbok



azaperone, midazolam, blesbok, cardiorespiratory function, chemical immobilisation, etorphine


The study compared immobilisation of blesbok (Damaliscus pygargus phillipsi) with etorphine and azaperone vs etorphine and midazolam. Twelve female blesbok, weighing 59.4 ± 2.8 kg, were used. Each animal randomly received Treatment 1 (T1) (etorphine, 0.07 ± 0.003 mg/kg + azaperone, 0.36 ± 0.02 mg/kg) and Treatment 2 (T2) (etorphine, 0.07 ± 0.003 mg/kg + midazolam, 0.20 ± 0.01 mg/kg) with a one-week washout period between treatments. Induction times were recorded followed by physiological monitoring for 45 minutes of immobilisation. Immobilisation was reversed with naltrexone (20 mg per mg etorphine). Recovery times were also recorded. Induction, immobilisation and recovery were scored with subjective measures. Inductions and recoveries did not differ between combinations, but the quality of immobilisation was significantly better with T1. Rectal temperature and blood pressure were  significantly lower during T1. Both treatments resulted in severe hypoxaemia and impaired gas exchange, although overall hypoxaemia was more pronounced for T1. Animals treated with T2, however, exhibited a deterioration in respiration as the monitoring period progressed, possibly as a result of impaired ventilatory muscle function due to the effects of midazolam. Both combinations are suitable for adequate immobilisation of blesbok and should be selected based on the specific capture situation. Supplementation with oxygen is highly recommended.

Author Biographies

L L Laubscher, Wildlife Pharmaceuticals (Pty) Ltd

Wildlife Pharmaceuticals (Pty) Lt and Department of Animal Sciences, Faculty of Agriscience, Stellenbosch University, South Africa

L C R Meyer, University of Pretoria

Centre for Veterinary Wildlife Studies and Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa

M Laurence, Murdoch University

School of Veterinary Medicine, College of Science Health Engineering and Education, Murdoch University, Western Australia

J P Raath, Wildlife Pharmaceuticals (Pty) Ltd

Wildlife Pharmaceuticals (Pty) Ltd., South Africa

S Pfitzer, Tshwane University of Technology

Department of Nature Conservation, Tshwane University of Technology, South Africa






Original Research