Evaluation of Medetomidine-Alfaxalone and Medetomidine-Ketamine in Semi-Free Ranging Bennett's Wallabies (Macropus rufogriseus)

Abstract

Twenty-six adult semi-free-ranging Bennett's wallabies were anesthetized. Animals in group MA received medetomidine 0.1 mg/kg and alfaxalone 4 mg/kg i.m. in a 5-ml dart, whereas those in group MK received medetomidine 0.1 mg/kg and ketamine 5 mg/kg i.m. in a 3-ml dart. Dosages were based on estimated body weights. The wallabies were allowed to recover spontaneously or, if still nonresponsive at the end of the procedure, were given atipamezole 0.5 mg/kg (half the dose via i.m. and the other half via i.v.). Heart rate and respiratory rate were monitored at 5-min intervals, temperature at 10-min intervals, and two arterial blood samples were taken for blood gas analysis. Statistical analysis was performed by using analysis of variance (P < 0.05). The use of 5-ml darts in group MA compared with 3-ml darts in group MK could potentially increase the risk of iatrogenic trauma and should be considered. Induction and maintenance of anesthesia were satisfactory in both groups. There were no significant differences between the groups in mean time to first effect, recumbency, and approach, or to time to sternal recumbency and standing after reversal with atipamezole. Although bradycardia was present in both groups, no statistical differences were calculated for respiratory rate and heart rate, whereas the mean cloacal temperature was significantly lower in group MA (P = 0.01). Mixed acid-base disturbances occurred in both groups. All but one animal in group MK needed atipamezole at the end of the procedure. No adverse effects were observed after recovery.

Cardiovascular and respiratory effects, and quality of anesthesia produced by alfaxalone administered intramuscularly to cats sedated with dexmedetomidine and hydromorphone

“…IM alfaxalone (4 mg/kg) did not cause excitement at induction or recovery in wallabies sedated concurrently with medetomidine. 4 Marmosets received 10 mg/kg alfaxalone IM, which would require a very large volume, but no comments were made regarding discomfort or reaction to the injection, and most of the marmosets were euthanased, so no recovery data are available. 5 Rabbits sedated with medetomidine received 5 mg/kg alfaxalone IM followed by isoflurane, and the induction and recovery were reported to be 'uneventful', but the recovery was actually not observed continuously.…”

Efficacy and Animal Welfare Impacts of Novel Capture Methods for Two Species of Invasive Wild Mammals in New Zealand

“…One wallaby died a short-time (<5 min) post-capture from net-gunning (i.e., it was found lying in an open area and on checking was found to be dead). The cause of death was inferred to be capture myopathy [41], possibly due to hyperthermia, as capture staff believed the CT for this animal was longer than for other netted individuals (the CT for this individual was not recorded on video camera, but was probably greater than 2 min). However, the body temperature of this individual (35.3 • C) was intermediate within the observed range of temperatures (34.4-37.0 • C) for other helicopter-chased wallabies, albeit based on a sample of only four individuals.…”

MASS CAPTURE AND ANESTHESIA OF AUSTRALIAN BRIDLED NAILTAIL WALLABIES (ONYCHOGALEA FRAENATA) WITH THE USE OF MEDETOMIDINE AND KETAMINE

“…There have been a number of recommended dose-rates of medetomidine and ketamine to anesthetize macropods including: (1) 0.05 mg/kg of medetomidine and 5 mg/kg of ketamine for docile red kangaroos (Macropus rufus) and western grey kangaroos (Macropus fuliginosus) (Holz 2007); (2) 0.1 mg/kg medetomidine and 5 mg/kg ketamine for Bennetts wallabies (Macropus rufogriseus) (Bouts et al 2011); (3) 0.04 mg/kg medetomidine and 4 mg/kg ketamine for eastern grey kangaroos (Macropus giganteus) (Pye and Booth 1998); and (4) 0.04-0.012 mg/kg medetomidine with 3-5 mg/kg ketamine (Vogelnest and Portas 2008) for macropods in general. To our knowledge, no specific recommendation has been reported for BNTW.…”