Immobilisation of African buffalo (Syncerus caffer) with low dose thiafentanil in combination with medetomidine and azaperone

To assess the physiological effects and efficacy of immobilisation with low dose thiafentanil in combination with medetomidine and azaperone in African buffalo. Observational prospective cohort study. Forty-one African buffalo selected opportunistically during immobilisation events at nine game ranches and reserves. Buffalo (12 males, 29 females; 9 calves, 32 adults) were immobilised with thiafentanil, medetomidine and azaperone. Recumbency and recovery times were recorded. Immobilisation quality was scored (0–4; poor to excellent). Physiological data were recorded using a stethoscope, digital thermometer and pulse oximetry. Arterial blood samples were collected in 21 animals. Venous blood was collected for biochemical analyses. Oxygen (4–6 L minute -1 ) was delivered via nasal insufflation in 13 buffalo, with paired arterial blood samples from eight animals to explore effects on oxygenation. Naltrexone (20–25 mg animal -1 ) was given intravenously following procedure completion. Data are presented as median (interquartile range). Doses were 0.0038 (0.0033–0.0043) mg kg -1 thiafentanil, 0.0042 (0.0038–0.0050) mg kg -1 medetomidine and 0.050 (0.044–0.057) mg kg -1 azaperone, based on estimated body weights. Immobilisation and recovery times were 7.5 (6–9) and 2.0 (1.1–2.0) minutes, respectively. Immobilisation quality was good to excellent in 36 buffalo. Heart rate was 64 (55–76) beats minute -1 , respiratory rate 24 (20–32) breaths minute -1 , peripheral haemoglobin oxygen saturation 82 (72–85)% and rectal temperature 39.6 (38.3–40.5) °C. All 41 buffalo were hypoxemic, based on pulse oximetry and/or arterial blood gas analysis, and 17 were hyperthermic. For the eight buffalo with paired arterial blood samples, oxygen supplementation improved PaO 2 , with six becoming normoxaemic. This protocol resulted in rapid immobilisation, good to excellent immobilisation quality, and rapid recovery. However, hyperthermia and hypoxaemia were major concerns. Nasal insufflation of oxygen was a simple and effective method to improve arterial oxygenation.