Evidence-Based Veterinary Medicine in Finfish Aquaculture in Newfoundland and Labrador

The Newfoundland and Labrador (NL) aquaculture industry is a major contributor of salmon products that help meet protein needs for the world's growing population. The industry in NL continues to grow and evolve and now includes emerging species in its production such as Atlantic cod. In a growing industry, with additional species being cultured, there are many opportunities to enhance evidence-based veterinary medicine (EBVM). The multifaceted process of EBVM includes critically evaluating published literature related to a particular question. Randomized controlled trials (RCT) are considered the best source of information with respect to interventions, but these trials are challenging to implement in an aquaculture setting. The aquaculture industry and their veterinarians need access to quality RCT in order to make sound, scientifically based health decisions. Therefore, it is the responsibility of the aquaculture industry and their veterinarians to assist in building this knowledge base to further advance the industry. The Newfoundland and Labrador Department of Fisheries and Aquaculture, together with the Centre for Aquatic Health Sciences, have worked with the NL industry and their veterinarians to answer questions while contributing to the process of EBVM.;The specific objectives of this research program evolved over time, but were all generally focused on the need for information in support of EBVM. The research focused on two objectives: evidence in support of trial execution and evidence from trials. The Passive Integrated Transponder (PIT) tagging study in Atlantic cod was developed to determine tag placement and evaluate adverse effects with such tag placement. This study was consistent with the first objective. The second objective was addressed by developing three clinical trials relevant to the NL industry at the time. These clinical trials were in response to questions around choosing treatment modalities for Eubothrium crassum, the option to use a nutraceutical during the smoltification stage of salmonid production and the use of a salmonid dip vaccine in Atlantic cod.;The tagging trial showed that there was no negative effect on survival and growth in Atlantic cod in the short term, thereby providing evidence to support the use of PIT tags in future studies.;The clinical trials showed (1) that treatment modalities adapted from terrestrial models do not provide predictable results when information is simply transferred, (2) that nutraceuticals need to be critically evaluated with respect to their label claims, and (3) that vaccination of Atlantic cod may provide protection against pathogens not included in the vaccine due to non-specific immunity.;The studies included in this thesis have contributed to the knowledge base used to inform aquaculture veterinarians who utilize EBVM. The results also highlighted techniques to obtain this information in an aquaculture setting.