The fight to keep the flesh-eating fly out of the Rio Grande Valley and away from the animals has been renewed. 

There are no confirmed cases of the screwworm in the Valley, but there is one near Uvalde and it now has ranchers on their toes.

Edinburg veterinarian Lucas Hinojosa remembers looking over his grandfather's and dad's cattle when he was young.

"Calves were losing their ears," Lucas said.

He especially remembered the outbreaks of the New World Screwworm in the late 1960s and 70s.

"When I was involved in treating as a kid, calves, and we would find navels that were swollen and bleeding," Lucas said.

He says the screwworm killed off some of his family's cows. The ones that lived lost value because of the injuries caused by the parasite.

"The damage it does is pretty extensive," Lucas said.

Out on the ranch, Hinojosa's wife, Norma, checks out their cattle.

"The cow will have a cut, well yeah, we'll have to worry," Norma said.

The screwworm can also impact other wildlife.

The Hinojosas say deer often come onto their property. They say the deer and cattle don't intermingle, but it's a point of concern.

Workers at Hacienda Hinojosa are going to have to start checking cows every single day during feeding time to see if they have any cuts or gashes on them that could be susceptible to the screwworm.

For ranch owners like Lucas, the warning to keep an eye on wounds goes for pet owners as well.

"Inspecting your animals and looking for any kind of suspicious wounds on your pets and on your livestock," Lucas said.

Be sure to also report it to the Texas Animal Health Commission and your vet.

Hidalgo County Judge Richard F. Cortez issued the following statement regarding the screwworm:

"We are closely monitoring the situation involving the New World screwworm recently reported in Zavala County. While there have been no reported cases in Hidalgo County, we are taking this matter seriously and are working closely with our state partners, including the Texas Animal Health Commission and the Texas Department of State Health Services, to ensure we are prepared should a case arise in our region.

We are also in communication with the county judges of Cameron, Starr, and Willacy counties to coordinate efforts and share information as developments occur. Protecting the health of our communities, livestock, and agricultural industry remains a top priority.

According to the U.S. Department of Agriculture, the New World screwworm was detected in a three-week-old calf in Zavala County. Federal and state officials have responded quickly by establishing a unified incident command structure, implementing quarantines and movement controls in the affected area, increasing surveillance and trapping efforts, and deploying sterile fly releases to help prevent the spread of the pest.

We encourage livestock owners and residents to remain vigilant and report any concerns involving animals with unusual or worsening wounds, the presence of larvae, or abnormalities around body openings or the navels of newborn animals. Report any suspicious wounds or maggots to your private veterinarian and the Texas Animal Health Commission. Early detection and rapid reporting are critical to preventing the spread of the screwworm.

At this time, there is no threat to the food supply. The USDA has confirmed that New World screwworms do not infest meat, fruits, vegetables, or other food products.

Hidalgo County will continue to work with local, state, and federal partners to monitor the situation and provide timely updates to the public as new information becomes available."

Cameron County Judge Eddie Treviño also issued the following statement regarding screwworm:

On June 3, 2026, the U.S. Department of Agriculture (USDA) confirmed the first case of New World Screwworm (NWS) in the United States, identifying an infected calf in Zavala County, Texas. Federal and state animal health officials are actively responding to the detection by establishing an infested zone, conducting animal and fly surveillance, carrying out epidemiological investigations, and implementing established response protocols to prevent further spread.

While Zavala County is located approximately 300 miles from Cameron County, county officials have been in communication with the appropriate state and federal agencies to ensure local departments remain informed, prepared, and ready to assist response efforts while protecting animals under county care.

Cameron County is also working to increase public awareness and encourage livestock owners, pet owners, veterinarians, and animal caretakers to closely monitor animals for signs of infection and report any suspected cases immediately.

The confirmation follows ongoing regional coordination efforts among Rio Grande Valley county judges (Cameron, Hidalgo, Starr, and Willacy), state agencies, and animal industry partners. During a regional press conference held on May 18, 2026, local leaders discussed the potential threat posed by New World Screwworm and emphasized the importance of preparedness and public awareness.

New World Screwworm can affect livestock, wildlife, pets, and other warm-blooded animals, particularly those with open wounds or sores. While infestation in humans is rare, residents are encouraged to remain vigilant and promptly report any suspected cases.

If you suspect New World Screwworm in an animal, immediately contact the Texas Animal Health Commission at 1-800-550-8242.

Current eradication efforts rely on the release of sterile male flies, a proven method that prevents reproduction and helps eliminate screwworm populations. Currently, there are sterile flies from a reproduction facility in Panama that are being released in South Texas. A large-scale sterile fly production facility is also being constructed by USDA in Edinburg, Texas and is expected to be completed in November 2027.

For additional information on New World Screwworm and best practices regarding monitoring, prevention, and treatment procedures, visit the Texas Animal Health Commission's New World Screwworm information page: https://www.tahc.texas.gov/emergency/nws.html

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