Mass capture and anesthesia of Australian bridled nailtail wallabies (Onychogalea fraenata) with the use of medetomidine and ketamine

Abstract

We anesthetized 301 bridled nailtail wallabies (Onychogalea fraenata), captured within Scotia Sanctuary, New South Wales, Australia over four nights in October 2009 to perform health assessments before their release into a predator-proof exclosure. We tested two anesthetic dose-rate combinations, protocol 1 (0.08 mg/kg medetomidine-4.5 mg/kg ketamine), and protocol 2 (0.1 mg/kg medetomidine-5 mg/kg ketamine), each given intramuscularly. Median time from injection to recumbency for protocol 1 was 10 min (1-27 min) and for protocol 2 was 12 min (2-28) (P = 0.12). Five animals died during the induction with protocol 2; none died with protocol 1 (P = 0.06). Physiologic parameters were recorded during recumbency, with no significant abnormalities with protocol 1. Protocol 1 was an effective, efficient regime to anesthetize large numbers of bridled nailtail wallabies under field conditions.