MERCEDES, Texas (RFD News) — Concern is growing across South Texas livestock country as ranchers and veterinarians warn that New World screwworm could pose significant monitoring challenges for cattle producers, particularly on large-scale operations.
Farmers and ranchers throughout the region say they are increasingly turning to local veterinarians for guidance as fears rise over the pest’s potential spread. While officials continue surveillance and response efforts, those on the ground say day-to-day herd management is becoming more complicated.
Brooks County veterinarian Dr. Mike Vickers says producers are already adjusting their treatment protocols and relying more heavily on preventive care and access to medication.
“We’re giving out information every day and selling medication that they can follow up and utilize if they don’t have access to it from other sources,” Vickers said. “Dectomax is one of them. Coral spray is another one. I’ve got a special preparation I mix up and give orally to horses.”
Vickers says the greatest risk is not always widespread infestation, but rather infection in vulnerable animals — particularly newborn calves.
“The first animals that are infected are newborn calves, and the screw worms get in their navel,” Vickers explained. “So they may want to change a protocol on how they treat their cattle or how they work their cattle operation, become more proactive and make sure that those animals are maybe treated the day they’re born.”
In Hidalgo County, cattle producer Mike Risica says his operation, which buys feeder cattle and finishes them for slaughter, is closely monitoring herd health. He says animals are typically moved quickly through the production system, but vigilance remains essential.
“We buy cattle, and we fatten them,” Risica said. “So we’ll buy them at around 500 pounds, and we’ll get them to about 1,300 pounds, and we send them directly to a packer.”
Risica says the pest tends to target open wounds or newborn animals, making routine observation critical for detection.
“The screw worm develops, and they start to eat the flesh,” he said. “That usually happens on baby calves or a cut on an animal. So if we have an injury out here, that’s probably pretty much the only place that’s going to happen.”
He added that frequent pen checks help his operation stay ahead of potential problems.
“We ride pens, you know, twice a day, so the cowboys are looking at those cattle,” Risica said. “So for us, it’s a lot easier to spot.”
However, both producers and veterinarians acknowledge that not all operations have the same level of labor or monitoring capacity. Dr. Vickers says large ranches across South Texas face growing challenges in maintaining intensive oversight of livestock.
“My neighbor on the north, that’s a 45,000 or 50,000-acre ranch,” Vickers said. “And back in the 70s, he had 30 mounted cowboys working seven days a week… You couldn’t find 30 cowboys in South Texas to work seven days a week.”
He noted that modern labor constraints and competing industries have made that level of hands-on monitoring increasingly difficult.
Vickers says additional manpower may still be available on a limited basis, but operations are adapting to a more constrained workforce environment.
As concerns continue to grow, both ranchers and veterinarians stress the importance of vigilance, early detection, and communication with animal health professionals.
Mike Risica emphasized that the issue centers on animal health rather than food safety.
“The screwworm is an animal welfare issue and not a problem with the food,” he said. “The food supply is not affected at all.”
Correspondent Frank McCaffrey reporting for RFD News.
