Anaesthesia of nyala (Tragelaphus angasi) with a combination of thiafentanil (A3080), medetomidine and ketamine

D.V Cooper,W Lance,M Bush,D Jessup,D Grobler

doi:10.4102/jsava.v76i1.388

Abstract

A combination of thiafentanil (A3080), medetomidine hydrochloride (MED) and ketamine hydrochloride (KET) was evaluated in 19 boma-habituated (12 female and 7 males) and 9 free-ranging nyala (7 male and 2 females) (Tragelaphus angasi) to develop a safe and reliable anaesthesia protocol. Wide dosages were used safely during this study with ranges for A3080 of 45 +/- 8 microg/kg with MED of 69 +/- 19 microg/kg and KET of 3.7 +/- 1.0 mg/kg (200 mg/ animal). The dosages developed on boma-habituated nyala proved to be equally effective in 9 adult free-ranging nyala (7 males and 2 females). The optimum dosage for nyala was a combination of A3080 (40-50 microg/kg), MED (60-80 microg/kg) plus 200 mg of KET/animal. The anaesthesia was characterised by a short induction, good muscle relaxation and mild hypoxaemia during monitoring the anaesthesia was rapidly and completely reversed by naltrexone hydrochloride (30 mg/mg of A3080) and atipamezole hydrochloride (5 mg/mg of MED) given intramuscularly. There was no mortality or morbidity associated with this protocol.

Highlights

Nyala (Tragelaphus angasi) are popular and economically important species stocked on many South African game farms and a flagship species in selected national parks
The improved quality of the anaesthesia and muscle relaxation was correlated to the increasing dosage of medetomidine hydrochloride (MED) rather than an increasing dose of A3080
Ketamine has synergistic properties with both MED3,11 and opiates[16] which decrease the dosages of MED and A3080 and gains the dissociative properties of ketamine hydrochloride (KET) to assist in the rapid down time

Summary

Introduction

Nyala (Tragelaphus angasi) are popular and economically important species stocked on many South African game farms and a flagship species in selected national parks. They prefer a habitat of dense bush, which leads to complications when field anaesthetic protocols with long induction times are used. Nyala are fairly delicate antelope with thin skin and are predisposed to stress and capture myopathy[6,7,14]. Nyala are captured by a net method[2,7] and given a tranquiliser as rapidly as possible to prevent stress and myopathy[6,7].

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