Evaluation of immobilisation using a fixed-dose combination of butorphanol, azaperone, and medetomidine, along with a low dose of ketamine, in chacma baboons (Papio ursinus).

BACKGROUND

Current literature most commonly describes the use of the dissociative drug ketamine for the immobilisation of baboons, either on its own or in combination with other drugs such as α-2 agonists or benzodiazepines. Currently, no reversal is available for ketamine, leading to prolonged and often rough recoveries of the animals, especially if high doses of ketamine are used.

OBJECTIVES

In this study, the fixed-dose combination of butorphanol, azaperone and medetomidine (BAM) with a low dose of ketamine (K-BAM) was evaluated for immobilisation and recovery parameters of chacma baboons.

METHODS

Fifteen baboons were immobilised and monitored. Actual doses administered: BAM 0.01 ± 0.005 ml/kg (butorphanol 0.31 ± 0.15 mg/kg, azaperone 0.12 ± 0.06 mg/kg, medetomidine 0.12 ± 0.06 mg/kg) and ketamine 2.04 ± 0.22 mg/kg. During immobilisation, heart rate (HR), respiration rate (RR), peripheral oxygen saturation (SpO2), end-tidal carbon dioxide (EtCO2), noninvasive blood pressure (BP) and blood gases were evaluated.

RESULTS

Inductions were reached in 3.46 ± 1.36 minutes. Overall, severe hypoxaemia (SpO2: 62 ± 13%; PaO2: 37 ± 10 mmHg) was observed in all baboons as well as elevated EtCO2 (63 ± 9 mmHg) and PaCO2 (63 ± 9 mmHg) values. Other measured parameters stayed within normal ranges. Recoveries were fully reached at 4.8 ± 2.8 minutes after intramuscular injection of the reversal naltrexone and atipamezole.

CONCLUSION

BAM with a low dose of ketamine produced short-term immobilisation, allowing for minor veterinary procedures. The severe hypoxaemia observed in all animals, however, raises serious concerns regarding the safety of this protocol.