Epsilon Open Archive

Abstract

Improvement of chemical capture is an important part of wildlife conservation and animal welfare to minimise distress for the animals and the risk of morbidity and mortality. The aim of this thesis was to improve wildlife immobilisation and anaesthesia by studying physiological variables and clinically evaluate different drug combinations and methods of capture in selected species. Reversible anaesthetic protocols were developed for use in free-ranging lions and four species of South- East Asian primates. Capture and anaesthesia of free-ranging wolverines, brown bears, black and white rhinoceros were physiologically evaluated. The effect of intranasal oxygen supplementation on arterial oxygenation was assessed in brown bears and rhinoceros. Partial reversal of the opioid effect and different body positions were evaluated in rhinoceros. Capture methods used included darting from a helicopter or the ground, and physical restraint followed by drug injection. Medetomidine-ketamine was used in wolverines and medetomidine-zolazepam-tiletamine in primates, lions and brown bears. Rhinoceros were immobilised with a combination of an opioid, azaperone and an alpha2-agonist. Body temperature and cardiorespiratory variables were monitored in all animals. Arterial blood samples were analysed to interpret pulmonary gas exchange and acid-base status in carnivores and rhinoceros. Low doses of medetomidine-zolazepam-tiletamine rapidly anaesthetised primates and lions, and reversal with atipamezole resulted in a smooth and calm recovery. Physiological alterations varied with different protocols and species and included changes in body temperature, respiratory and heart rates, gas exchange and acid-base balance. Hypoxaemia was recorded in all rhinoceros and most carnivore species. The major contributor to hypoxaemia was likely ventilation-perfusion mismatch including shunt. In rhinoceros, hypoventilation contributed to an impaired gas exchange and the animals remained hypoxaemic despite partial reversal. However, in black rhinoceros arterial oxygenation was higher during sternal compared to lateral recumbency. Capture-induced lactic acidaemia was recorded in carnivores and rhinoceros. Intranasal oxygen supplementation improved arterial oxygenation. In conclusion, this thesis increases the understanding of the effects of capture and anaesthesia in several wildlife species. Physiological derangements were identified, potential causative factors were investigated and methods for improvement were evaluated.