Overview
A dangerous livestock pest called New World screwworm has been detected in Mexico, just 60 miles south of Texas. This has prompted Florida to restrict animal imports from six South Texas counties near the Rio Grande Valley. While screwworm hasn't been found in the United States yet, the threat is serious enough that states are taking protective action. New World screwworm is a parasite where flies lay eggs in open wounds on livestock, pets, and sometimes people. The eggs hatch into maggots that eat living tissue, which can kill animals and cause serious health problems. This matters to Houston-area residents because Texas has a massive livestock industry worth billions of dollars. If screwworm spreads into Texas, it could devastate ranches, drive up meat prices, and hurt our state's economy. The pest was last found in the United States a decade ago, and it took major efforts to eliminate it. Texas Agriculture Commissioner Sid Miller is monitoring the situation closely and working with other states on prevention. Livestock owners should watch their animals for unusual wounds or signs of infection. Veterinarians are on alert for suspicious cases. If you work with animals or live in rural areas, report any unusual animal health issues to your veterinarian or the Texas Department of Agriculture immediately.
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“Florida restricts Texas livestock imports due to screwworm threat detected in Mexico, protecting agricultural industries from dangerous parasites.”
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Six Texas counties in the Rio Grande Valley are the subject of state-level scrutiny — more than 1,000 miles away. Florida is restricting animal imports from the Lone Star State amid the threat of screwworm detections.
New World screwworm (NWS) is not currently in the United States, though Texas Agriculture Commissioner Sid Miller said a case has been confirmed in Nuevo Leon, Mexico, 60 miles south of Texas.
As a result, Florida is targeting several "high-risk" counties in South Texas, requiring any livestock animals imported from those counties to undergo increased veterinary screenings and treatment.
"We know how costly and dangerous this pest can be to our agricultural industry if it takes hold, and we will use every tool at our disposal to protect our state," Florida Agriculture Commissioner Wilton Simpson said in a news release on Friday. "We're also calling on Florida's producers, veterinarians, and animal health professionals to remain aware and act quickly if they suspect something unusual."
New World screwworm is a pest that affects livestock, pets and, less commonly, people and birds. Flies lay eggs in open wounds and body openings, then hatch into parasitic maggots that burrow into and feed on tissue and flesh, according to the Centers for Disease Control and Prevention.
Florida’s emergency rule applies to Zapata, Jim Hogg, Starr, Hidalgo, Webb and Brooks counties in Texas. Though the rule would apply to any "high-risk" county in the United States, it currently only applies to those Texas counties.
"Florida's move is understandable," Miller said in a statement. "With the growing threat of New World screwworm, and as ground zero of America's last outbreak a decade ago, they're acting to protect their state. This isn't a distant risk, and their heightened biosecurity makes that clear."
Under Florida's emergency rule, animals imported into Florida from high-risk counties must be inspected by veterinarians. Animals that are admitted and have wounds must be using an effective treatment.
Though screwworms have not been found in the United States, all ports of entry at the southern border are closed to livestock trade.
The U.S. Department of Agriculture is developing a sterile fly production facility at Moore Air Base in Edinburg to combat the spread of NWS. Female screwworms can mate only once, and this facility will sterilize NWS flies. Those sterile flies will be released into the wild, mating with other screwworms, producing eggs that won't hatch and reducing population growth. This facility is expected to be operational in November 2027.