South Texas Watches Closely as New World Screwworm Threat Grows

Nearly everyone in the South Texas ag community appears extremely worried about the potential of a New World screwworm epidemic, according to a local veterinarian. RFD NEWS Correspondent Frank McCaffrey reports.

FALFURRIAS, Texas (RFD NEWS) — With recent reports of the dangerous New World screwworm in Mexico, concern is growing across South Texas. The parasitic fly can cause myiasis and feeds on live tissue, posing a serious threat to livestock, wildlife, and pets.

A recent statement by Texas Agriculture Commissioner Sid Miller on RFD News’ Market Day Report drew significant attention, warning producers that the pest is moving closer to the U.S. border.

“You need to start checking your livestock, checking your pets, it’s going to be across the border. I hate to say that, but it’s inevitable,” Miller said.

South Texas Veterinarian Dr. Mike Vickers says there are already confirmed cases in a northern Mexican state that borders Texas.

“They’re in Tamaulipas. There was a calf left probably around 200 miles or less from the Texas border that showed up with screwworms in the navel, and of course, they’re dropping flies all over Tamaulipas right now,” Vickers said.

What he calls a very real threat appears to be getting closer.

“Some of the experts are telling me that they really expect to see them in the spring. All this cold weather we’re having in South Texas is really a great situation for pushing them back. But when it starts warming up in the spring, we’re expected to see them,” Vickers said.

Vickers has firsthand memories of screwworm outbreaks from decades past and says the economic toll was devastating. He tells RFD-TV he has seen people lose hundreds of calves — losses that would amount to millions of dollars in today’s market.

“Back in the ‘70s, the ranchers in South Texas had almost a hundred percent infection rate in newborn calves and with the screwworms getting in their navel. And that would weaken the calves, they’d stop nursing, and then the coyotes would come in and gobble them up,” Vickers said.

He has also witnessed the damage screwworms can cause when they infest the ears of cattle and horses.

“Not only in the cattle, but in the horses. So after it was all said and done, we got it cleared up. All of his cattle had no ears. They looked like a new breed with no ears because he’d had a big crew of cowboys working seven days a week, running those cows through the chute and treating them, catching the calves, treating their navels. And then his horses were earless also,” Vickers said.

The bottom line, according to Vickers, is that screwworms can severely impact a wide range of livestock and wildlife species.

RFD-TV reporter Frank McCaffrey asked Dr. Vickers how much concern the reports out of Mexico have created in South Texas and whether producers are reaching out with questions.

“Oh, absolutely. I’m getting calls from the people that have exotic wildlife, people that have hunting leases, people that have captive deer operations, and cattle breeders. Also, people who raise sheep and goats,” Vickers said.

Vickers says concern is widespread, adding that nearly everyone in the South Texas agricultural community appears extremely worried about the potential for a screwworm epidemic.

Related Stories
Alan Bjerga with the National Milk Producers Federation joined us to review new policies and regulations supporting the dairy industry and what they mean for the year ahead.
Despite rising costs and growing food insecurity, meat demand remained strong in 2025 as higher-income consumers offset cutbacks elsewhere. Economists break down the K-shaped economy, upcoming USDA cattle reports, livestock production outlooks, and renewed debate over beef imports and country-of-origin labeling heading into 2026.
Midland County Livestock Association President Brandon Mitchell reflects on another strong year for the event, including a premium sale that once again topped the million-dollar mark.
Livestock strength is carrying the farm economy, while crop margins remain tight and increasingly dependent on risk management and financial discipline.
Protein-driven dairy growth is boosting beef supply potential, creating an opening to support rural jobs and ground beef availability.
In a landmark ruling delivered in late 2025, the U.S. Supreme Court significantly narrowed the scope of the National Environmental Policy Act.
RFD NEWS Correspondent Frank McCaffrey speaks with Texas’s Sen. Ted Cruz and Rep. Vicente Gonzalez about USMCA renegotiation and its impact on U.S.–Mexico agriculture trade.
The Midland County Junior Livestock Show in West Texas features a competitive steer showcase highlighting top-quality cattle and the accomplishments of driven youth exhibitors.
Texas Commissioner of Agriculture Sid Miller joined us to discuss data center expansion, farmland preservation, rural economic impacts, and imminent cattle biosecurity concerns affecting agriculture today.

Agriculture Shows
The goal of “Where the Food Comes From” is as simple as its name implies — host Chip Carter takes you along on the journey of where our food comes from — and we don’t just mean to the supermarket (though that’s part of the big picture!). But beyond where it comes from, how it gets there, and all the links in the chain that make that happen.
Join markets specialist Scott Shellady, better known as the Cow Guy, as he covers the market-close, breaking down headlines that drive the commodities and equities markets with commentary from respected industry heavyweights.
Crop yield champions David Hula from Virginia and Randy Dowdy from Georgia are back for another season with the aim of schooling more growers across the country in their winning ways.
“Texas Agriculture Matters” is a fun, informative look at the role of agriculture in our daily lives. The show utilizes the trademark wit and wisdom of its host Commissioner Sid Miller — an 8th-generation farmer-rancher and 12-time World Champion rodeo cowboy — to explore a new Texas ag-related topic each week.