BILLINGS, Mont. - Cattle just north of Yellowstone National Park will be tested for the disease brucellosis after a bull bison was caught among them, the state veterinarian said Tuesday.

Tom Linfield said about two dozen cattle that had been vaccinated against brucellosis will be given a blood test.

Linfield declined to provide the owner's name but said that bison have been out among livestock in the area several times already this winter after leaving the park.

Authorities killed the bison, which also got in among horses near Gardiner and "took after" state and federal officials who'd tried to chase it, said Marc Bridges, executive director of the state Department of Livestock.

Blood was taken from the bison to test for brucellosis, Linfield said.

Many Yellowstone bison have brucellosis. The potential for transmission of the disease between bison and cattle is at the center of a state-federal management plan that allows for the hazing or capture of bison that stray into Montana. Brucellosis can cause cows to abort and, should it turn up in cattle, could cost the state its prized brucellosis-free status.