BORIS Theses

BORIS Theses
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Video-based identification of surrogate endpoints in experimental bacterial infections of rainbow trout (Oncorhynchus mykiss)

Keeling, Caroline Marie (2018). Video-based identification of surrogate endpoints in experimental bacterial infections of rainbow trout (Oncorhynchus mykiss). (Thesis). Universität Bern, Bern

18keeling_c.pdf - Thesis
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To identify visually perceptible clinical signs that would enable timely distinction between survivors and nonsurvivors in infection experiments requiring death as experimental endpoint, rainbow trout were recorded on video after being subjected to bacterial challenge with Aeromonas salmonicida and Yersinia ruckeri. Deviations from normal morphology, behaviour and movement patterns were analysed for their potential to predict death in infected animals kept in groups of 10 fish inside small volume holding tanks (15 l). It was found that clinical signs reflecting a highly debilitated physiological state, like inability to hold an upright position or being passively dragged by a current, offer high sensitivity and specificity, but are largely inefficient in reducing the overall time an animal spends inside the experiment. A change in body shape detected in fish infected with A. salmonicida, provided high sensitivity and earlier identification of nonsurvivors. Anorexia was identified as a promising death predictor in terms of sensitivity and timely identification, but its specificity was likely to be confounded by a high level of social aggression observed between the fish. As expression of early clinical signs in form of sickness behaviour might have been strongly influenced by experimental husbandry conditions, it is assumed that optimisation of those could present an effective approach for improving applicability of surrogate endpoints in this species.

Item Type: Thesis
Dissertation Type: Single
Date of Defense: 2018
Additional Information: e-Dissertation (edbe)
Uncontrolled Keywords: humane endpoints - rainbow trout - death predictor - social aggression - sickness behaviour
Subjects: 500 Science > 590 Animals (Zoology)
Institute / Center: 05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP) > Center for Fish and Wildlife Health (FIWI)
Depositing User: Admin importFromBoris
Date Deposited: 25 Jan 2019 12:56
Last Modified: 31 Jan 2019 15:51

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