File photo by Wesley Aston/Shutterstock

Elk in southwestern Montana were exposed to brucellosis, based on the results of a brucellosis surveillance from a 2018 elk capture operation.

According to officials with Montana Fish, Wildlife & Parks, elk were captured in the Tendoy Mountains and eastern side of the Madison Valley.

Of the 100 elk sampled in the Tendoy Mountains, one was found to have been exposed to brucellosis (seropositive). This is the first time an elk has tested positive for exposure in the Tendoys. The Tendoys are currently outside of the Designated Surveillance Area (DSA), an area in which livestock brucellosis testing and traceability requirements exist.

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To learn more about the movement patterns of the elk and understand how the disease may spread, 30 elk in the Tendoys were fitted with radio collars.

In the southeastern Madison Valley, an area within the DSA, 6 elk tested positive for exposure out of the 41 sampled there. Forty of the animals were outfitted with collars.

“The discovery of an exposed elk in the Tendoys emphasizes the importance of elk surveillance near the boundary of the DSA,” said Montana State Veterinarian Martin Zaluski, “We appreciated this partnership with FWP which helps us continue to identify livestock potentially at risk.”

Officials say the goal of brucellosis surveillance operations is to evaluate the presence and understand the movement of brucellosis in Montana’s elk populations. The research helps to understand the overlap between elk and livestock on the landscape.

According to FWP, Brucellosis is a bacterial disease that infects cattle, bison, and elk and can result in abortion or the birth of weak calves. The disease is primarily transmitted through contact with infected birth tissues and fluids.

Animals that test positive for brucellosis were exposed to the bacteria at one time and have developed antibodies that can be measured with blood tests.

More information about brucellosis and the Targeted Elk Brucellosis Surveillance project can be found here.

Montana Department of Livestock regulations can be found online here.