Flesh-Eating Screwworm Outbreak Confirmed in Texas Livestock
The USDA confirmed the first U.S. cases of New World screwworm since 2017 in two calves in Zavala County, Texas. The parasitic larvae feed on living tissue, threatening livestock and agriculture. Authorities established a 20-km infested zone, enforced quarantines, and released sterile insects to contain the outbreak. Canada restricted livestock imports from affected areas. The USDA expressed confidence in eradicating the pest, citing past success.
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New screwworm case confirmed in Texas
The U.S. Department of Agriculture has confirmed a sixth case of New World screwworm in a Texas calf, marking the second infested calf in La Salle County. The parasite poses a serious threat to livestock as its larvae burrow deep into host tissue, causing severe wounds and potential death. Officials in Texas are monitoring the situation and implementing control measures to prevent further spread. The outbreak highlights ongoing risks to the livestock industry and the need for vigilance in animal health surveillance.
Just In NewsU.S. confirms second Texas screwworm case, Canada restricts livestock imports
The U.S. Department of Agriculture confirmed a second case of New World screwworm, a flesh-eating parasite, in a one-month-old calf in Zavala County, Texas, about 5.6 miles from the first case. The larvae feed on living tissue of warm-blooded animals and can be fatal if untreated. In response, the Canadian Food Inspection Agency temporarily restricted imports of livestock, including horses, from affected U.S. areas, banning animals that were in Texas within 21 days of crossing the border. USDA officials emphasized the detection occurred within an existing movement-control zone where sterile insects are being released to suppress the pest. USDA stated the U.S. food supply remains safe, as screwworms do not infest food products and affected animals are caught during inspection. Officials expressed confidence in eradicating the pest, citing past success.
US Top News and AnalysisU.S. confirms second Texas screwworm case, Canada restricts livestock imports
The U.S. Department of Agriculture confirmed a second case of New World screwworm, a flesh-eating parasite, in a one-month-old calf in Zavala County, Texas, about 5.6 miles from the first case. The larvae feed on living tissue of warm-blooded animals and can be fatal if untreated. In response, the Canadian Food Inspection Agency temporarily restricted imports of livestock, including horses, from affected U.S. areas, barring animals that were in Texas within 21 days of border crossing. USDA officials emphasized the detection occurred within an existing movement-control zone where sterile insects are being released to suppress the pest. USDA stated the U.S. food supply remains safe, as screwworms do not infest food products and affected animals are intercepted during inspection. Under Secretary Dudley Hoskins expressed confidence in eradicating the pest again.
US Top News and AnalysisUSDA Confirms Second Flesh-Eating Screwworm Case in Texas
The U.S. Department of Agriculture (USDA) confirmed a second case of New World screwworm, a flesh-eating parasite, in a one-month-old calf in Zavala County, Texas, on Friday. The detection follows testing of multiple suspected cases as authorities race to contain and eradicate the outbreak before it severely impacts the cattle population. The screwworm infestation poses a significant threat to livestock, and the USDA is mobilizing resources to prevent further spread.
Just In NewsFlesh-eating screwworm confirmed in Texas, first US case since 2017
The USDA confirmed the first US detection of New World screwworm since 2017 in a 3-week-old calf in Zavala County, Texas. The larvae, which burrow into living animal flesh, were found in the calf's umbilical area. USDA and Texas officials established a 20-kilometer infested zone, enforced quarantines, and launched surveillance to contain and eradicate the pest. The USDA noted the pest was eradicated in the US in 1966 and a 2017 Florida outbreak was eliminated. In December 2025, the FDA conditionally approved Merck's Exzolt Cattle-CA1 topical solution to prevent and treat infestations. Merck shares rose over 3.5% on the news. Senator Ted Cruz called the detection serious and pledged support for eradication efforts.
US Top News and AnalysisFlesh-eating screwworm confirmed in U.S. for first time in decades
The U.S. Department of Agriculture confirmed the detection of New World screwworm (Cochliomyia hominivorax) in a bovine in Zavala County, Texas. A three-week-old calf was found with larvae in its umbilical area, marking the first confirmed case in the United States in recent years. No further detections have been reported. USDA and Texas officials are implementing immediate containment and eradication measures, including establishing a 20 km infested zone, enforcing quarantines, movement controls, and surveillance. The screwworm is a parasitic fly whose larvae feed on living tissue, posing a threat to livestock and potentially causing significant economic losses to the agricultural sector. USDA stated it has invested heavily in elimination tools since cases increased in Central America and Mexico, and expressed confidence in eradicating the pest again.
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