Abstract:
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.
