New Mexico state veterinarian Dr. David Fly confirmed bovine tuberculosis was found in a herd in a Curry County dairy outside the zone where TB was detected three years ago.
The U.S. Department of Agriculture prohibits cattle from being moved in or out of the zone, which includes parts of Curry and Roosevelt counties.
Three other dairies outside the zone are under investigation, Fly said. He would not name the dairies. So far, the state's TB-free status has not changed.
"We're working with the USDA to find out if anything will happen with our TB-free status," Fly said. "How much we find and how soon we can clean it up (determine) whether it'll change our status."
Fly said the investigation for one dairy should be completed next week, and there appears to be no sign of the disease in that herd. "We have to see if other animals have left the dairy that might have exposed another dairy," Fly said.