The Montana Department of Livestock has reported a brucellosis case in a heifer within Montana’s Designated Surveillance Area (DSA).

Image/US Department of Interior, US Geological Survey
Image/US Department of Interior, US Geological Survey

The brucellosis-infected animal was first identified during voluntary herd testing on a Madison County ranch. Infection was confirmed by the National Veterinary Services Laboratory in Ames, IA by tissue culture following euthanasia of the animal. The ranch has been placed under quarantine and the department has initiated an epidemiological investigation. Testing of all other animals on the ranch is already underway.

“This animal previously tested negative in December of 2016, indicating this is a recent infection,” said State Veterinarian, Marty Zaluski. “Because of the continued risk of transmission from positive elk in the DSA, we expect transmission to domestic cattle or bison to occasionally occur.”

Producers with cattle or bison in the DSA are subject to increased identification and testing requirements.

“Through the significant efforts of veterinarians and producers, we are able to find these cases early and within the boundaries of our DSA, thus protecting our state as well as our trading partners,” Zaluski said.

This is the 9th brucellosis affected herd found since the creation of the DSA in 2010. In all three Greater Yellowstone Area states, elk have been determined to be the likely source of infection in livestock.