Gallatin County animal tests positive for brucellosis
Jordan Hansen
(Daily Montanan) An animal tested positive for brucellosis in Gallatin County, the state Department of Livestock reported in late December.
The state received confirmation that the animal was positive on Dec. 24, and the herd has been quarantined and an epidemiological investigation is “ongoing,” a news release said.
The Department of Livestock does not identify the species of animal as a rule for confidentiality.
Brucellosis is a bacterial disease that can spread between animals, attacking their reproductive system, and can cause abortions in pregnant cattle, elk and bison. The disease can be transmitted to humans, though Montana hasn’t had a positive human case in nearly a decade.
The surveillance areas are in southern and southwestern Montana, and are mostly areas near Yellowstone National Park. Some Yellowstone bison and elk test positive for brucellosis and can move up and intermingle with populations not in the park boundary.
While the source of the brucellosis transmission is not currently known for the Gallatin County animal, all 14 prior tests have come back as transmission from elk, the press release said.
The positive test is the 15th since 2010, when the Designated Surveillance Areas were put in place, the release said. The most recent case, prior to the Gallatin County one, was in Beaverhead County last year.
“Detections of brucellosis are inevitably burdensome for an operation,” Dr. Tahnee Szymanski, state veterinarian, said in a release. “Our goal at Montana Department of Livestock is that the work that (Designated Surveillance Area) producers do on an annual basis can be leveraged towards a highly tailored and focused investigation that reduces the impact to an operation when brucellosis is found.”
The state also outlined what disease investigations look like in the release, saying they may look as far as three years back in the herd’s history to see if the disease can be traced to any other herds.
“In this case, the affected herd does not utilize shared grazing, has a minimal number of herds that run adjacent, and conducts voluntary annual whole herd testing, resulting in a relatively small scope investigation,” the state press release said.
The Gallatin County animal in question was caught via “voluntary whole-herd testing” and was pregnant at the time of the positive test.
The animal “was removed from the herd before she was able to spread the disease through an abortion or during calving,” the release said, allowing the herd to be quarantined with “no expected impacts” to routine management practices.
Montana is considered to be brucellosis free, called “Class Free,” an important designation in the beef industry — if the state didn’t have it, livestock exported from anywhere in the state would need to be tested. Right now, only animals in what are called “Designated Surveillance Areas” are tested, to the tune of about 100,000 tests per year. It’s not cheap either — those tests ring up to more than $600,000 annually.
Vaccinations of cattle against brucellosis are also required to be performed by a licensed veterinarian. Vaccination requirements also apply to seasonal grazers.