USDA’s Animal and Plant Health Inspection Service (APHIS) officials confirmed the first U.S. case of New World screwworm (NWS) on June 3, found in a 3-week-old calf in southern Texas. As of June 9, six cases have been confirmed – five livestock in Texas and one dog in New Mexico.
USDA and Texas officials have taken immediate action to contain and eradicate NWS from the U.S., following the strategies and actions outlined in the NWS Response Playbook, including:
- Continuing the epidemiological investigation
- Sampling additional animals in the household
- Fly trapping
- Preparing for release of sterile insects should it be needed
- Conducting outreach in the area to encourage reporting of additional suspect cases
USDA’s National Veterinary Stockpile is also ready to be disbursed as resources including treatments, equipment and logistics support the response are needed. “This situation is evolving, and we expect new information to emerge as our investigation continues. USDA is committed to sharing what we learn quickly, accurately and transparently so animal owners and local communities have the information they need to stay vigilant,” Dudley Hoskins, undersecretary for marketing and regulatory programs, said in a USDA statement. “We are working closely with our partners in New Mexico, Texas and across the region to ensure we identify, contain and respond to any potential cases as swiftly as possible.”
The possibility of NWS crossing the Mexican border into the U.S. has been considered almost certain since reports of cases spreading through Central America and into Mexico sparked U.S. producer concerns throughout the last few years. However, through preemptive measures taken by the USDA and efforts made by our southern neighbors, the northern spread of NWS has taken longer than originally predicted. “All models showed New World screwworm entering the country in 2025; however, thanks to the hard work across the entire Trump administration and our industry, state and local partners, we were able to buy time for this moment,” said Hoskins. "Protecting our livestock industry is a national security issue of the utmost importance, and USDA is wasting no time in taking action. USDA invested heavily in the tools needed to eliminate NWS ever since cases started increasing in Central America and Mexico. The U.S. has defeated this pest before, and we will do it again.”
Guidance for pet and livestock owners
Close monitoring and immediate reporting of suspected cases will be critical to slowing the spread of NWS and treating cases before they cause irreparable damage to the animal. The USDA urges residents in at-risk areas to inspect animals daily for:
- Draining or enlarging wounds
- Maggots or egg masses
- Signs of discomfort or irritability
- Lesions around body openings (ears, nose, genital area, umbilicus)
Anyone who suspects an NWS infestation should immediately contact their veterinarian, state animal health official or the USDA. In Texas, report suspected cases in livestock directly to Texas Animal Health Commission officials by finding your closest area office here.
Food and animal safety
The USDA does not consider NWS a direct threat to the U.S. food supply. According to the APHIS NWS website, screwworms do not infest meat, fruits, vegetables or other food sources, and rigorous inspection protocols ensure that the nation’s commercial supply of meat, poultry and egg products is safe and properly labeled. Additionally, federal inspection personnel must inspect all eligible animal species unless they are exempt or covered by a state inspection program. Accordingly, any evidence of screwworm infestation in an animal would be identified during these inspections, and any contaminated product from an affected animal would not be allowed to enter the food supply.
The Canadian Food Inspection Agency (CFIA) has announced temporary restrictions on live animal imports from the U.S. Livestock, including horses, that originate from or were present in the state of Texas within 21 days prior to border crossing will not be accepted into Canada. Several U.S. states have also taken precautionary actions to mitigate the risk of spread.
