We evaluated a combination of nalbuphine, medetomidine, and azaperone (NalMed-A) in 12 American bison ( Bison bison ) during 13 sedation handling events. The mean (SE) dosage was 0.4 (0.02) mg/kg nalbuphine, 0.08 (0.003) mg/kg medetomidine, and 0.08 (0.003) mg/kg azaperone contained in an average delivery volume of 0.8 mL/100 kg. Two animals required a supplemental dose for safe handling (additive dose used in calculating means) and a third animal was not adequately sedated despite a supplemental dose. Bison immobilized with NalMed-A showed good sedation in 12 of 13 handling attempts. Advantages of this drug combination included a relatively low delivery volume, rapid antagonism, and minimal regulatory burden for component drugs. The most consistent disadvantage was hypoxemia, and oxygen supplementation is recommended when using this sedative combination in bison.
Keywords: Azaperone; bison; blood gas; chemical immobilization; medetomidine; nalbuphine.