Texas on Alert After New World Screwworm Detected 120 Miles from Border

December 4, 2025 – AUSTIN — Texas Agriculture Commissioner Sid Miller is urging vigilance after federal officials confirmed a new case of the New World screwworm (NWS) in northern Mexico, marking the closest detection to Texas in years.

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) verified the parasite in a 22-month-old bovine transported from Veracruz to a feedlot in Montemorelos, Nuevo León — roughly 120 miles south of the Texas border. It is the second detection at the same facility since October; both appear linked to livestock movements from southern Mexico rather than local transmission.

Miller called the screwworm “one of the most devastating livestock pests ever encountered in North America,” noting the parasite’s ability to infest wounds and kill animals if not quickly treated. While stressing that Texas remains free of the pest, he warned ranchers and state agencies not to let their guard down.

“Texas ranchers feed the nation, and our herds are too important to risk,” Miller said. “We’ll continue working hand-in-hand with USDA and Mexican animal-health officials to defend the border and keep this threat out of Texas.”

State officials are asking producers — especially near the border — to monitor livestock, pets, and wildlife for unusual wounds or maggot activity and report any suspicions immediately. Early detection and rapid response remain key to preventing an outbreak.