A combination of alfaxalone, medetomidine and midazolam for the chemical immobilization of Rhesus macaque (Macaca mulatta): Preliminary results

BACKGROUND Chemical immobilization of non-human primates can be required to perform scientific or veterinary procedure with different invasiveness degrees. This preliminary study was undertaken to assess the clinical effects of a combination of alfaxalone, medetomidine and midazolam (AMM). METHODS Seven rhesus macaques were chemically immobilized, for invasive veterinary procedures, with alfaxan 2 mg kg-1 , medetomidine 20 μg kg-1 and midazolam 0.3 mg kg-1 injected subcutaneously. RESULTS The alfaxalone combination induced surgical anaesthesia, with a complete absence of response to noxious stimuli, for at least 20 minutes. The total duration of anaesthesia was 56 ± 7 minutes, and the administration of atipamezole, to partially reverse the combination effects, did not appear to alter the depth of anaesthesia. CONCLUSION In conclusion, the AMM combination produced rapid onset general anaesthesia, following subcutaneous administration of a relatively low volume (0.28 mL/kg) of injectate.