Elk may have been the source of the disease in the bison.
State livestock officials are investigating a second confirmed case of brucellosis in Park County and a possible new case in Sublette County, both in Wyoming.
Wyoming Assistant State Veterinarian Bob Meyer says the new case in Park County involves a herd of 1,400 bison. The state is working with the owner to test the entire herd. Three surrounding cattle herds also are being tested, even though the bison are fenced in, Meyer says.
It's suspected that elk may have been the source of the disease in the bison.
"We want to make sure that any of the surrounding herds right around there didn't get the same exposures to the elk because the elk can jump over fences both ways," Meyer says.