Eco-epidemiology of production limiting diseases at the wildlife-livestock interface: beef cattle and elk in southwestern Alberta, Canada

Date
2014-08-15
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Abstract
The circulation of pathogens at the wildlife-livestock interface have great consequences for conservation, livestock production and public health. In southwestern Alberta, interactions between cattle and elk (Cervus elaphus) can be opportunities for pathogen transmissions. In this study, we explored the inter-species transmission of livestock pathogens between cattle and elk. Diagnostic tests initially developed for cattle were evaluated and adapted for use in elk. The occurrence of five pathogens (Bovine Herpesvirus 1, Bovine Viral Diarrhoea virus, Mycobacterium avium subsp. paratuberculosis- MAP, Neospora caninum and Fascioloides magna) in geographically overlapping cattle and elk herds was assessed in relation to the pathogen transmission route. Finally, the spatio-temporal patterns of interactions between cattle and elk were described: we first assessed factors influencing the use of cattle pasture by elk, and then defined and measured different types of interactions corresponding to different pathogen characteristics and transmission routes. Only pathogens with indirect transmission routes (MAP, N. caninum, and F. magna) were found in both elk and cattle. Pathogens that persist in the environment, or within intermediate or definitive hosts, may have more opportunities for indirect transmissions, as they do not rely on strict spatio-temporal proximity. This was also illustrated by the increase in interaction rates when the definitions of “interaction” were based on increasing length of pathogen persistence in the environment. Elk avoided cattle presence, except during winter months, possibly increasing direct contacts at this period. When direct contact is necessary for pathogen transmission, specific features of the ranch, such as cultivated hay land, mineral supplements, water sources may also play a critical role by attracting elk on pastures in closer proximity to cattle. This study highlighted the need for the evaluation and validation of diagnostic tools for wildlife species. It contributed to identify the combined effects of pathogen characteristics and inter-species interactions on the transmission of multi-host pathogens. Finally, it identified the benefit of integrating the diversity of pathogen characteristics and life cycles into descriptions of inter-species interaction patterns, and the need for detailed livestock management information to provide reliable assessments of these interactions.
Description
Keywords
Veterinary Science, Epidemiology
Citation
Pruvot, M. (2014). Eco-epidemiology of production limiting diseases at the wildlife-livestock interface: beef cattle and elk in southwestern Alberta, Canada (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25778