BOZEMAN, Mont. -

State livestock officials are expanding an animal disease surveillance program to new areas of southwest Montana where infected elk were found.

The Bozeman Daily Chronicle reports that the expansion covers 365 miles of Gallatin County between Norris and Three Forks.

Ten of 60 elk recently captured in the area along the Madison River west of Bozeman tested positive for exposure to brucellosis. The disease can cause pregnant animals to prematurely abort. It has been widely eradicated in livestock but persists in wildlife in and around Yellowstone National Park.

The expanded area would require roughly 50 livestock producers to test around 12,000 cattle at a cost of $30,000 annually.

Department of Livestock spokesman Steve Merritt says the new boundaries are subject to public comment but won't change unless new issues arise.