SAN ANTONIO – The New World screwworm has surfaced again in south Texas, putting the cattle and ranching community on high alert.
Federal agriculture officials confirmed the first case of New World screwworm in a horse in Presidio County near the Mexican border on Wednesday.
We have been following the resurgence of this flesh-eating parasite, which was listed on Sept. 9 as one of only two active cases in the country – the other involving a dog in Crockett County detected Aug. 31.
The Texas Animal Health Commission immediately banned the movement of warm-blooded animals out of a designated “infested” zone surrounding Presidio and Jeff Davis counties in hopes of containing the outbreak and protecting the multibillion-dollar livestock industry. Officials estimate a widespread outbreak could cost the Texas economy up to $1.8 billion.
The U.S. Equestrian Federation reported the parasite was found in the hind limb of a working ranch horse and urged all horse owners to take action.
“We encourage every horse owner to help protect their horses and the broader equine community by practicing good wound care, fly control and biosecurity,” the organization said in a statement.
The return of screwworm has reignited debates around cattle imports and beef prices. President Trump announced Friday that up to 300,000 pounds of foreign beef will be sold in the U.S. over the next 90 days at 25 percent below current market prices. This announcement follows a recall of nearly 30,000 pounds of beef from Argentina that did not undergo required federal re-inspection, leading to a Class I health hazard designation by the USDA’s Food Safety and Inspection Service.
As teams race to improve trapping technology and identification, sterile screwworm flies are also being released in affected regions to disrupt the breeding cycle and slow the parasite’s spread. While new lures and traps are still in development, officials continue to study the best ways to protect Texas livestock and maintain the health of the cattle industry.