Please read the abstract in the section, 09summary, of this document / Thesis (PhD (Zoology))--University of Pretoria, 2008. / Zoology and Entomology / PhD / unrestricted

Wild animal capture has progressed over the years from trapping or physical capture, which was dangerous to both animal and man, to chemical immobilization. Opioids and butyrophenones are the most common classes of drugs used for ungulate immobilization; however newer drugs and drug combinations are commonly used in an attempt to reduce time to immobilization in wildlife. The enzyme hyaluronidase is often added to drug combinations in the belief that it reduces time to immobilization by improving drug absorption. The primary objective of this study was to ascertain if the addition of hyaluronidase to an etorphine and azaperone drug combination would be of value in reducing time to immobilization in blue wildebeest. The study also tried to ascertain if the added hyaluronidase enabled one to reduce the etorphine and azaperone doses required to immobilize blue wildebeest, without affecting time to immobilization. The study made use of a four-way cross-over study design, with four treatment groups, four sequences and four periods. The four treatment groups were etorphine and azaperone; etorphine, azaperone and 5000 international units (IU) hyaluronidase; etorphine, azaperone and 7500 IU hyaluronidase; and 75 % of the original etorphine dose, 75% of the original azaperone dose and 7500 IU hyaluronidase. Each animal was immobilized with each of the above four drug combinations randomly over an eight week period with a two week interval between each period. The times to first effect, first down and immobilization were recorded. The etorphine and azaperone treatment group was used as the control group. The difference in time to first effect between the control group and the etorphine, azaperone and 7500 IU hyaluronidase treatment group was statistically significant (95 seconds versus 67 seconds; p = 0.007). When compared to the time to immobilization in the control group (323 seconds) the time to immobilization in the etrophine, azaperone and 5000 IU hyaluronidase (228 seconds); etorphine, azaperone and 7500 IU hyaluronidase (210 seconds) and the low dose etorphine, low dose azaperone and 7500 IU hyaluronidase (268 seconds) groups were statistically significantly reduced (p=0.002, p=0.001 and p=0.045 respectively). It is therefore concluded that the addition of 5000 or 7500 IU hyaluronidase to an etorphine and azaperone combination significantly reduced the time to immobilization in blue wildebeest. The unexpected decrease in time to immobilization in the low dose etorphine, low dose azaperone and 7500 IU hyaluronidase treatment group requires further investigation. / Dissertation (MMedVet)--University of Pretoria, 2011. / Production Animal Studies / unrestricted

La trazodone est une drogue antagoniste et agoniste dose-dépendante de la sérotonine utilisée en médecine humaine et vétérinaire pour le traitement de troubles reliés à l’anxiété. Le trauma a été identifié comme la cause primaire de morbidité et de mortalité chez plusieurs espèces de ruminants sauvages et peut être exacerbé par le stress. Dans une étude récente chez la chèvre domestique, la trazodone a réduit les niveaux d’activité sans effets secondaires. La trazodone a le potentiel de réduire le stress et de permettre des captures et manipulations plus sécuritaires chez ces espèces. Les objectifs de cette étude étaient d’identifier une dose de trazodone résultant en une diminution du niveau d’activité chez une espèce de ruminant sauvage, le gnou bleu (Connochaetes taurinus), d’évaluer la sécurité de cette dose et ses effets sur les concentrations de cortisol sérique suivant une procédure vétérinaire de routine. Une étude pilote effectuée à l’aide d’éthogrammes a permis d’identifier une dose orale de 15 mg/kg comme étant efficace pour réduire les niveaux d’activité. Cette dose a mené à une augmentation de 111% du temps passé à dormir/se reposer (P = 0.0003) et de 41% du temps à être couché (P = 0.0016) et une diminution 64% du temps passé à bouger (P = 0.005) et de 65% du temps passé à être vigilant (P = 0.026). La concentration systémique de trazodone mesurée 2 heures suivant l’administration était de 95 ± 48 µg/L. Les concentrations de cortisol sérique durant une procédure de prise sanguine n’ont pas été significativement modifiées par l’administration de trazodone (P > 0.05). Le seul effet adverse noté avec la dose de 15 mg/kg était la baisse d’appétit, ce qui n’était pas présent avec la dose de 12 mg/kg évaluée lors du projet pilote. La trazodone apparaît sécuritaire et prometteuse pour la diminution de l’activité chez le gnou bleu et ainsi pour avoir des effets positifs sur leur bien-être et la sécurité des ruminants sauvages lors de procédures vétérinaires. / Trazodone is a dose-dependant serotonin antagonist and agonist used in human and veterinary medicine to treat anxiety-related conditions. Trauma has been identified as the leading cause of morbidity and mortality in several wild ruminant species and can be exacerbated by stress. In a recent study in domestic goats, trazodone reduced activity levels without adverse effects. Trazodone could allow for safer capture and handling in ruminant species. The objectives of the present study were to identify a dose of trazodone that decreases activity levels in captive blue wildebeest (Connochaetes taurinus), to evaluate its effects on serum cortisol levels following a routine veterinary procedure, and its safety. A pilot study using ethograms identified a 15 mg/kg oral dose of trazodone as effective to reduce activity levels. Over 6 hours, this dose resulted in a 111% increase in time spent sleeping/resting (P=0.0003), a 41% increase in time spent lying down (P=0.0016), a 64% reduction in time spent moving (P=0.005), and a 65% reduction in time spent being vigilant (P=0.026). Systemic absorption of trazodone was identified when plasma concentrations were measured after 2 hours (95 ± 48 µg/L). Serum cortisol levels during a routine venipuncture event were not significantly different following trazodone adminstration (P > 0.05). Mild hyporexia was the only adverse effect noted at 15 mg/kg and was absent at a 12 mg/kg dose. Trazodone appears safe and promising to decrease activity in the blue wildebeest and might thus have a positive effect on wild ruminant welfare and the safety of veterinary procedures.