Cattle are herded in a stable on June 5, 2026 in Dublin, Texas.
Brandon Bell | Getty Images
The U.S. Department of Agriculture confirmed a second case of New World screwworm, a flesh-eating parasite, in Texas.
The latest detection was found in a one-month-old calf in Zavala County, Texas, roughly 5.6 miles from the first confirmed case announced earlier this month, the USDA’s Animal and Plant Health Inspection Service said Friday. Additional samples collected from the surrounding area have tested negative so far.
New World screwworm larvae feed on the living tissue of warm-blooded animals, creating severe wounds that can be fatal if left untreated. The pest threatens livestock, wildlife, pets and, in rare instances, humans.
The discovery has triggered cross-border restrictions. The Canadian Food Inspection Agency said Friday it will temporarily restrict imports of livestock, including horses, from affected areas of the U.S. Animals that originated in or were present in Texas within 21 days before crossing the border will not be permitted entry into Canada.
Federal and state officials emphasized that the second case was detected within an existing movement-control zone established after the initial finding and that it remains within an area where sterile insects are being released to suppress the pest’s population.
“USDA has not wasted any time in this fight, we have defeated New World screwworm before, and we will do it again,” Dudley Hoskins, the agency’s Under Secretary for Marketing and Regulatory Programs, said in a statement.
USDA said the U.S. food supply remains safe despite the detections. New World screwworms do not infest meat, fruits, vegetables or other food products, according to the agency. Any affected animal would be identified during inspection, and no contaminated product would be allowed to enter commerce, it said.
“Livestock owners and all Texans should remain vigilant,” Texas Farm Bureau President Russell Boening said in a statement. “Surveillance and reporting are a priority. The quicker an infestation is found, the quicker the New World screwworm can be eradicated.”
This story is developing. Please check back for updates.