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Practicality of using impala (Aepyceros melampus) as a research model

Thesis (PhD)--University of Pretoria, 2018.

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Other Authors: Meyer, Leith Carl Rodney
Format: Thesis
Language:English
Published: University of Pretoria 2018
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access_status_str Open Access
author2 Meyer, Leith Carl Rodney
author_browse Meyer, Leith Carl Rodney
author_facet Meyer, Leith Carl Rodney
collection Thesis
dc_rights_str_mv © 2018 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Thesis (PhD)--University of Pretoria, 2018.
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institution University of Pretoria (South Africa)
language English
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license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2018
publishDateRange 2018
publishDateSort 2018
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/65522 Practicality of using impala (Aepyceros melampus) as a research model Meyer, Leith Carl Rodney gareth.zeiler@up.ac.za Zeiler, Gareth Edward UCTD Impala Hypoxaemia Hypercapnia Game farming Veterinary science theses SDG-03 Veterinary science theses SDG-09 Veterinary science theses SDG-12 Thesis (PhD)--University of Pretoria, 2018. This thesis focus on providing information that furthers our understanding on the practicality of using impala (Aepyceros melampus) as a model for research regarding the effects of immobilisation and general anaesthesia on wildlife generally and wild ungulates specifically. Impala have been used as a research model for around seven decades, but deaths have been reported, especially in experiments where free-ranging impala are placed under captive conditions. There are currently no reports investigating the cause of these deaths. Therefore, the risks involved when using impala in research studies are not entirely known. This paucity in the literature magnifies plausible concerns regarding research ethics and animal welfare that require consideration when using free-ranging animals. This thesis comprises of a series of studies which focus on 1) determining and evaluating the physiological effects of various drug combinations used to immobilise and anaesthetise impala, and 2) determining factors that place free-ranging impala at risk of injury or death when captured and placed into captivity under intensive research conditions. Fifteen adult female impala were enrolled into the 16- week long project. In the first study reported in this thesis, both thiafentanil-medetomidine and etorphine-medetomidine drug combinations successfully immobilised impala, however, despite seemingly normal heart and respiratory rates, all impala were hypoxaemic. Calculated ventilation and oxygenation indices suggested that the hypoxaemia was primarily attributed to right-to-left intrapulmonary shunt of blood. However, other causes of dysfunction in gas exchange such as increased dead space ventilation or ventilation to perfusion mismatch or alterations within the alveolicapillary membrane diffusion, or combinations of all of the above aetiologies for hypoxaemia are plausible. Opioid-induced hypoventilation was not considered a primary cause of the hypoxemia because measured minute volumes were within an appropriate range for medium sized antelope. The second study in this thesis determined if an etorphine-ketamine-medetomidine constant rate infusion was a practical method of maintaining general anaesthesia in impala for up to 120 minutes. However, hypoxaemia, hypercapnia and acidosis were sufficient to require intervention if this protocol is used in the field. The third study evaluated the acid-base status of impala undergoing immobilisation and general anaesthesia using two different drug combinations. In both cases, there was a moderately progressive respiratory acidosis compensated by a marked metabolic response. Both the Henderson- Hasselbalch and the Stewart approaches could explain the acid-base status in the impala. The fourth study determined and discussed the risk factors that resulted in morbidity and mortality in the impala throughout the study period. We found that darting injuries were the highest risk factor that resulted in the most impala deaths during our study. The last study reviewed chemical capture of impala to highlight all the major risks contributing to morbidity and mortality of impala in clinical practice. The greatest risks emanate from the drug and drug delivery factors, where potent opioids (etorphine and thiafentanil) cause profound respiratory compromise, that if left untreated often translates into fatalities. Furthermore, the procedure of darting, an essential tool in game capture, can cause irreparable fractures and other fatal injuries mainly through accidental misplacement of the dart into a long bone, thoracic or peritoneal cavity. Impala are anxious and flighty, and this demeanour (animal related factor) can contribute towards morbidity and mortality rates. The findings of these studies highlight that impala serve as a useful model for improving immobilising and anaesthetic drug protocols, darting techniques or new methods of remote injection in wild antelope. In order to improve animal welfare and the success of similar studies in impala, it is essential that the risks and physiological effects of chemical capture and anaesthesia are well understood before embarking on similar studies. Paraclinical Sciences PhD Unrestricted SDG-03: Good health and well-being SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production 2018-07-13T06:48:27Z 2018-07-13T06:48:27Z 2018/04/20 2018 Thesis Zeiler, GE 2018, Practicality of using impala (Aepyceros melampus) as an anaesthesia research model, PhD Thesis, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/65522> A2018 http://hdl.handle.net/2263/65522 en © 2018 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Impala
Hypoxaemia
Hypercapnia
Game farming
Veterinary science theses SDG-03
Veterinary science theses SDG-09
Veterinary science theses SDG-12
Practicality of using impala (Aepyceros melampus) as a research model
title Practicality of using impala (Aepyceros melampus) as a research model
title_full Practicality of using impala (Aepyceros melampus) as a research model
title_fullStr Practicality of using impala (Aepyceros melampus) as a research model
title_full_unstemmed Practicality of using impala (Aepyceros melampus) as a research model
title_short Practicality of using impala (Aepyceros melampus) as a research model
title_sort practicality of using impala aepyceros melampus as a research model
topic UCTD
Impala
Hypoxaemia
Hypercapnia
Game farming
Veterinary science theses SDG-03
Veterinary science theses SDG-09
Veterinary science theses SDG-12
url http://hdl.handle.net/2263/65522