Screwworm Livestock

Signage is seen as U.S. Agriculture Secretary Brooke Rollins holds a news conference at the Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, Texas, Monday, June 8, 2026.

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A flesh-eating cattle parasite spreads beyond Texas as new screwworm cases are found

A flesh-eating cattle parasite spreads beyond Texas as new screwworm cases are found

Three more cases of the New World screwworm have been confirmed, including one outside Texas, demonstrating the difficulty of stopping a pest that could potentially devastate the nation’s cattle industry. The U.S. Department of Agriculture announced Monday the new cases were found in a dog from New Mexico and hundreds of miles away in a goat and calf in Texas. The screwworm is actually a fly, which produces a larva that eats live flesh instead of dead material. Females lay their eggs in open wounds any any warm-blooded animal such as cattle, but wildlife, pets and occasionally even humans can be infested. Before it was irradicated in the 1960s, the fly was an annual warm-weather scourge of cattle ranchers.