BILLINGS, Mont. -

An animal disease surveillance program has found elk that have been exposed to brucellosis in an area of southwest Montana where infections previously had not been documented.

State Veterinarian Marty Zaluski said Tuesday that 10 of 60 elk captured in an area along the Madison River west of Belgrade tested positive for exposure to the disease.

Tests on 70 elk from a second area, the Tobacco Root Mountains, found no evidence of infection.

Brucellosis can cause pregnant animals to prematurely abort. It has been widely eradicated in livestock but persists in elk, bison and other wildlife in and around Yellowstone National Park.

Zaluski says authorities anticipated the disease would turn up in the area where it was found and have been working with ranchers to make sure cattle are tested.