A federal government plan to carve out the Yellowstone area as an animal disease "hot-zone" faces opposition from some state veterinarians, who worry the move would lower cattle industry safeguards.

Creation of the zone would recognize Yellowstone as the last remaining region in the country where the disease brucellosis lingers. That could ease sanctions faced by some cattle producers when infections occur.

State veterinarians from across the country had backed the idea last year at an annual convention in North Carolina. But several have since said their support hinges on stepped-up efforts to curb the disease in Yellowstone's wildlife - something they say hasn't yet occurred.

Brucellosis has been eradicated elsewhere in the country but persists in Yellowstone's elk and bison herds.