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

OBJECTIVE

To assess the physiological effects and efficacy of immobilisation with low-dose thiafentanil in combination with medetomidine and azaperone in African buffalo.

STUDY

DESIGN

Observational prospective cohort study.

ANIMALS: A group of 41 African buffalo selected opportunistically during immobilisation events at nine game ranches and reserves.

METHODS

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 per animal) was administered intravenously following procedure completion. Data are presented as median (interquartile range).

RESULTS

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 PaO2, with six becoming normoxaemic.

CONCLUSIONS AND CLINICAL RELEVANCE: 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.