BILLINGS, Mont. (AP) -- State officials say livestock producers in seven Montana counties must get their cattle tested for brucellosis before the end of the year.
Some cattle producers may be able to avoid testing all of their animals if they complete a risk survey and are found to have a low risk of disease transmission from elk.
Elk in the greater Yellowstone region were the suspected culprits in all seven cattle herds that tested positive for the disease this decade.
The Yellowstone area is the last known reservoir of brucellosis in the nation.