A flesh-eating parasite that burrows into cattle and other livestock has some California ranchers concerned about a possible outbreak in the state after multiple cases were confirmed in Texas and New Mexico.

The U.S. Department of Agriculture announced on Monday that five cases of New World screwworm, or NWS, have been detected in Texas and New Mexico within the span of a week. Three calves and a goat in Texas were confirmed to have NWS, while the first case in a dog was detected in Lea County in New Mexico, the USDA said. The latter is believed to be an isolated case, but the USDA said it is investigating other animals while also reviewing the dog’s movement history, as the dog may have been in Mexico.