Hooijberg, Emma Henriette2022-01-122022-01-122021/04/162020*A2021http://hdl.handle.net/2263/83173MAST (MSc (Veterinary Science))--University of Pretoria, 2020.The African elephant (Loxodonta africana) is listed as Vulnerable on the Red List of the International Union for Conservation of Nature. Populations on the African continent have been declining for decades, through loss of habitat, human-elephant conflict, and hunting and poaching for ivory and bushmeat. Elephants are very popular zoo animals and numbers held in captivity across the globe are well within the thousands. Reference intervals (RI) are a valuable tool in monitoring health and disease status of populations and provide assistance with making diagnoses and determining prognosis in diseased individuals. Most publications reporting reference values for elephants provide information on limited measurands or have used small sample sizes, were conducted with outdated methods, or sampled either culled or captive animals. Moreover, no RI study has been performed for the African elephant according to the guidelines for RI generation provided by the American Society for Veterinary Clinical Pathology (ASVCP). The objectives of this study were therefore 1) to generate RIs for haematology, clinical chemistry and acute phase reactants (APR) in free-ranging African elephants, 2) to compare the established RIs to those already published, and 3) to assess changes in clinical chemistry of diseased animals, using these RIs. The ASVCP recommendations were followed throughout the process of RI generation. The reference sample population initially consisted of 79 apparently healthy free-ranging elephants from the Kruger National Park. Samples were collected from these elephants prior to the start of this study. Clinical chemistry analysis was performed on stored serum using the Large Animal Rotor on an Abaxis Vetscan VS2. Measurement of the acute phase reactants in serum was performed on the Roche Cobas Integra 400 Plus, using a colorimetric peroxidase assay for haptoglobin, the ferrozine zinc method for iron and an immunoturbidometric assay for serum amyloid A (SAA). Haematology analysis was performed at the time of sample collection using EDTA whole blood. Haematology samples were analysed with a Scil Vet ABC or a Horiba ABX Micros ESV 60 using the domestic horse setting. A manual packed cell volume was also performed. Blood smears were made for all animals, and these were examined, and a manual differential count performed, for this study. Statistical analysis was performed with the RefVal Advisor add on for Excel. Strict outlier identification and elimination was applied as the samples originated from a wild animal population and clinical examination was limited. Either parametric or non-parametric methods were used to generate the 95% reference intervals for the population, depending on the data distribution. The 90% confidence intervals (CI) of the lower and upper reference limits were calculated using a bootstrap method. An additional 17 samples from injured (all snare-related) animals were selected and analysed for the same clinical chemistry and APR measurands as described above and blood smears were evaluated for 200-cell differential count and morphological changes.en© 2021 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.UCTDDissertation