Brucellosis has been discovered in a Madison County cattle herd, the Montana Department of Livestock announced Thursday.
The disease, which has damaged Montana's beef economy previously, was confirmed in a Madison County cow through tests by the National Veterinary Services Laboratory in Ames, Iowa.
Brucellosis is an infectious disease that can cause abortions in cattle and wildlife. People can get the disease when they are in contact with infected animals or animal products contaminated with disease-causing bacteria. Reoccurring fevers, anorexia, arthritis and fatigue are common symptoms in humans.
“It’s unfortunate. We obviously don’t like finding brucellosis in our cattle, but the silver lining is that the program we’ve invested so much time and effort in is working,” said Marty Zaluski Montana state veterinarian in a press release. “The infected cow was found quickly.”
The state won't lose its Brucellosis-free Status, Zaluski said, because the infection occurred in a designated surveillance area in southwest Montana where brucellosis is known to exist in wildlife and is tightly managed in livestock. Sales of live Montana cattle to buyers out of state should continue uninterrupted.
Cattle sales are crucial to Montana's economy. Cattle number 2.6 million head in Montana. Sales in 2012 totaled $1.29 billion, according to the U.S. Department of Agriculture's National Agricultural Statistics Service.
Part of a 1,000 head herd, the infected female Angus was headed to slaughter when brucellosis was discovered in early September. The cow was “open,” meaning her womb was empty. Female cattle are often sent to slaughter in the fall if they’re not pregnant because winter feed is expensive and calf sales are how ranchers pay the bills.
Zaluski said the cow was about 30 months old and had been vaccinated for brucellosis in its first year.
Vaccinations are required for all cattle born in the southwest Montana region known as the Designated Surveillance Area. There, wildlife, including brucellosis-prone elk and bison from Yellowstone National Park migrate through portions of Beaverhead, Gallatin, Madison and Park counties.
Vaccines prevent abortions, which can spread brucellosis through bacteria exposure. But there’s still a slight possibility a vaccinated animal can be infected.
Since the surveillance area was created in 2009, brucellosis cases have been minimal. Eight animals from four herds have tested positive for the disease, though roughly 65,000 cattle live in the area, Zaluski said.
Similar surveillance areas exist in Wyoming and Idaho to curb brucellosis concerns in pastures surrounding Yellowstone National Park. As a result, for four years cattle sales across state lines have been uninterrupted whenever brucellosis has been detected, though the trend could be changing.
This month, Texas increased testing requirements for sexually in-tact surveillance-area cattle from Idaho, Montana and Texas. Montana exports roughly 6,000 breeding cattle to Texas annually.
Zaluski said the Texas requirement is unnecessary because Montana testing is getting the job done. In previous Montana cattle herds where brucellosis was discovered in a single animal, whole-herd tests revealed an infection rate of roughly 1 percent, Zaluski said.
“Fact is, we’re finding it, we’re finding it early, and we’re not letting infected animals make it to market,” Zaluski said. “We’ve got a good program that works well for our producers and keeps infected animals from entering interstate commerce.”