A Mixture of Butorphanol, Azaperone, and Medetomidine for the Immobilization of American Beavers ( Castor canadensis).

A total of 58 American beavers ( Castor canadensis) was immobilized with butorphanol, azaperone, and medetomidine (BAM) for the purpose of health assessments, sex determination, and placement of very high-frequency tail transmitters in a subset of animals. Isoflurane gas anesthesia was available to aid with induction when needed, and all animals received supplementary oxygen. Thirty-one beavers immobilized with a mean (SD) dose of 0.