Efficacy of a low-dosage combination of butorphanol, azaperone, and medetomidine (BAM) to immobilize Rocky Mountain elk.

We compared dosages of a combination of sedatives, which included butorphanol tartrate, azaperone tartrate, and medetomidine HCl (BAM) in captive adult Rocky Mountain elk (Germs elaphus nelsoni). All three BAM dosages (low, medium, and high) effectively immobilized elk and produced an adequate level of sedation in all subjects. Induction times were similar among the three groups (meant +/- SD: low=6.9 +/- 1.1 min; medium =6.3 +/- 0.9 min; high =4.7 +/- 1.3 min). Most elk became hypoxemic regardless of BAM dosage, but hypoxemia tended to be most severe in the high-BAM group; regardless of BAM dosage, oxygen supplementation improved the percentage of oxygen saturation and stabilized the vital rates. Recovery after administration of antagonists (3 mg atipamezole/mg medetomidine and 2 mg/kg tolazoline) was comparable among groups (range of means =9 +/- 1.5-11.7 +/- 1 min). Based on the findings from clinical trials and field data from free-ranging elk immobilizations, we recommend low-dose BAM (2 mL dose; equivalent to 46 mg butorphanol, 30 mg azaperone, and 18 mg medetomidine) and supplemental oxygen for adult elk; immobilization should be antagonized using 3-5 mg atipamezole/mg medetomidine and 2 mg/kg tolazoline, with tolazoline injected about 5-10 min before atipamezole to smooth out recovery.