October 26, 2018 | Vol. 11 : No. 10


Montana DOL Adopts New Brucellosis Rules

Montana expands Designated Surveillance Area and vaccination requirements for brucellosis.

The Montana Department of Livestock (MDOL) has adopted changes to rules affecting vaccination requirements and the boundary of the Designated Surveillance Area (DSA) for brucellosis, or Bang’s Disease.

The newly adopted brucellosis vaccination rule (ARM 32.3.433) mandates that eligible animals in 10 Montana counties must be vaccinated against brucellosis. The change requires that all sexually intact female cattle and domestic bison 12 months of age or older in Beaverhead, Big Horn, Broadwater, Carbon, Gallatin, Jefferson, Madison, Park, Stillwater and Sweet Grass Counties must be brucellosis-vaccinated. Prior to this rulemaking, only cattle and domestic bison in Gallatin, Madison, Park and Beaverhead counties were required to be vaccinated. This rule includes cattle that enter any of these counties for seasonal grazing.

“Vaccination has been shown to minimize the spread of the disease if it is introduced into a livestock herd.”
—Eric Liska

Beyond the addition of new counties, the rule also moves away from Dec. 1 as the cutoff date for completion of vaccination and no longer specifies that animals be vaccinated in calfhood. This gives producers more options for the management of replacement heifers and allows animals to be vaccinated as adults.

“Vaccination in a broader area than Montana’s DSA provides some protection from sudden changes to the distribution of infected wildlife on the landscape,” said Eric Liska, brucellosis program veterinarian with MDOL. “Vaccination has been shown to minimize the spread of the disease if it is introduced into a livestock herd.”

Producers who have not vaccinated their replacement females in the past should contact their local veterinarian to schedule replacement heifer vaccinations and discuss options for unvaccinated adult females in the herd.

Additionally, changes to ARM 32.3.433 adjust the DSA boundary in a portion of Beaverhead County. Cattle and domestic bison that utilize this area will be subject to all brucellosis DSA regulations. DSA regulations include brucellosis testing prior to change of ownership and movement, as well as vaccination and identification requirements.

The DSA boundary has expanded three times since 2009. Each expansion was made in response to findings of brucellosis in elk, which required the inclusion of additional cattle and domestic bison in the surveillance program. Undetected disease spread outside of Montana’s DSA could jeopardize Montana’s federal brucellosis Class Free status.

In 2008, a loss of brucellosis Class Free status was estimated to have cost Montana’s producers up to $11.5 million annually. DSA regulations and producer compliance have allowed for early disease detection when a periodic transmission from wildlife to livestock does occur. This success promotes trading partner confidence in the disease-free status of Montana’s livestock.

The mission of the Montana Department of Livestock is to control and eradicate animal diseases, prevent the transmission of animal diseases to humans, and to protect the livestock industry from theft and predatory animals. For more information on the Montana Department of Livestock, visit

Editor’s note: This article was provided as a news release by the Montana Department of Livestock. For more information, visit

Photo by Craig Simmons.