Infectious diseases that can jump between different species can be dangerous because they can also make the leap to humans. Wild animal markets have recently come under fire with the emergence of COVID-19, but these dangers are also present on Canadian farmland.
New research on seasonal affects on patterns of close contact between wildlife and livestock has provided a roadmap for how to minimize disease transmission.
“There is a long list of diseases that occur between livestock and wildlife, including anthrax, bovine tuberculosis, brucellosis, and many species of worms. And in addition to infecting one another, many of the diseases that are shared by wildlife and livestock are zoonotic, meaning that they also can infect humans.”
The University of Alberta and University of Calgary scientists used data from two sources to determine the times and places where the risk of transmission was highest. Cattle management data from 16 operations were combined with telemetry data from GPS tracking on 168 elks.
The winter months were a clear winner for disease transmission between the elk and livestock. During this season, the elk come down from their mountain territories and scavenge for leftover hay and salt licks on the ranches. This leads to a greater amount of interaction between the two populations than any other time of year.
Summer posed its own risks as cattle spread themselves over a larger pasture area and meetings at waterbodies were more common (late summer has previously been cited as a high-risk time). The more animals in the mix during these interactions, the higher the likelihood of transmission.
Naturally, there are large areas of land where humans aren’t around to frighten off wildlife and the two freely intermingle. As such, the authors developed some basic recommendations to lower the risk of transmission by keeping things closer to home during high-risk periods.
Minimizing contact with wildlife by maintaining livestock and resources (hay, water, minerals, etc.) in pastures close to farm buildings during winter and calving season is key, according to Boyce.
In a comment to the CBC, Lead author Mathieu Pruvot emphasized that there is no reason for ranchers to be alarmed. Rather, he believes it is important to be prepared and vigilant: “we know from other places that this type of interaction is a risk for disease transmission that can affect livestock production or wildlife conservation depending on the direction of transmission.”
In their concluding remarks, the researchers noted the importance of continuing to collect livestock management and wildlife-tracking data in parallel. This will help to continue monitoring the health of both groups and minimize the chances of an outbreak.