Five-year study will track brucellosis in elk

BILLINGS – Montana wildlife officials plan to capture 500 female elk over the next five years to track the spread of a disease that can threaten cattle.

The study is scheduled to begin this winter and will target brucellosis, which causes some animals to abort their young.

The disease is confined in the United States to the Yellowstone region of Montana, Idaho and Wyoming. Periodic infections over the last decade have prompted federal restrictions on the three states’ interstate beef trade.

The latest infection was announced this week in Wyoming, where three cattle from a Park County herd tested positive in a preliminary test. Livestock officials plan to test 3,000 head from surrounding herds to see if the infection is broader.

The Montana study is designed to help livestock and wildlife officials learn how to guard against future outbreaks. Researchers from the state Fish, Wildlife and Parks Department will take blood samples from 100 captured elk a year and radio collar those that test positive.

Wildlife veterinarian Jennifer Ramsey said the state plans to recapture brucellosis-positive animals annually. Elk that continue to test positive over five years would be killed for further tests on their tissue.

Brucellosis-positive elk also will receive vaginal implants with transmitters, to determine how easily the disease spreads through aborted birthing material.

State veterinarian Marty Zaluski said he hopes the results will clear up questions over how fast and where the disease is spreading among elk and the potential for more transmissions to livestock.

“We need to have a long-term strategy on where we see the disease in elk in the future, and if there are any trigger points where we intend to do something about it,” Zaluski said.

Brucellosis has been spreading for decades among the approximately 100,000 elk in and around Yellowstone National Park.

The disease was first brought to the region in the diseased livestock of early European settlers, and is now endemic to Yellowstone’s wildlife. In Montana, the infection rate for elk ranges from 5 to 12 percent.

Some livestock owners in the region have urged an aggressive response, including the possible slaughter of diseased elk. Sporting groups oppose the idea, and a Fish, Wildlife and Parks spokesman said slaughter did not offer a long-term solution.