APHIS has received updated guidance from SENASICA Mexico allowing for pet dogs to travel to Mexico according to previously established procedures while updated requirements are under negotiation. The following guidance will be updated on our public-facing IREGs and Pet Travel Website pages to reflect APHIS’ current understanding of export restrictions to Mexico:

NEW WORLD SCREWWORM NOTICE

Due to the detection of New World screwworm (NWS, Cochliomyia hominivorax) in the United States, effective immediately, halt exports of the following species from all U.S. States until we have further information from Mexico:

• Cattle (slaughter and reproduction)
• Wild ruminants (non-bovine)
• Equine (slaughter, breeding/work, and sport/exhibition/transit)
• Sheep and goats (slaughter and reproduction)
• Swine (reproduction)
• Ferrets (commercial and pets)
• Songbirds/ornamental birds/raptors (commercial and pets)

PET DOGS—UPDATE (June 10, 2026)

Pet dog travel to Mexico will proceed according to previously established procedures. Updated requirements will be posted to the Pet Travel Website once they are finalized.

ADDITIONAL GUIDANCE

As of November 22, 2024, Mexico is considered to be affected with screwworm. All dogs (including U.S.-origin dogs returning to the United States after traveling to Mexico) must meet APHIS requirements for screwworm freedom certification upon entry (re-entry) into the United States. Additional information can be found on the APHIS Dog Import Website.

• All New World Screwworm-related travel restrictions as relayed to USDA APHIS by US trading partners are being noted on the USDA APHIS webpages below.
• • APHIS International Regulations (IRegs) for non-pet species: https://www.aphis.usda.gov/live-animal-export
  • APHIS International Pet Travel website for pet species: https://www.aphis.usda.gov/pet-travel/us-to-another-country-export#modal-link-cdc-alert-export
• APHIS is still working with many trading partners, including Mexico, to clarify the restrictions/updated requirements. The USDA APHIS webpages will be updated just as soon as new information is received.
• They are asking that people not contact the USDA APHIS offices for additional information about country-specific restrictions, because USDA-APHIS doesn’t have additional information beyond what is posted to their webpages.
• USDA APHIS wants to emphasize that they are working quickly as possible with US trading parters and they appreciate patience and understanding as they work through complex issues.

WASHINGTON, D.C., June 8, 2026 – Today, the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed two additional cases of New World screwworm (NWS) in the United States – a calf in La Salle County, Texas, and a dog in Andrews County, Texas. 

Epidemiological investigations are ongoing for both cases. A veterinarian in Andrews County submitted the samples from the infested dog. Details on this case will be shared as they are available, but early reports indicate the dog was recently in Mexico. 

NWS is a serious pest that threatens livestock, pets, wildlife, and, in rare cases, people. The larvae burrow into the living tissue of animals, causing severe wounds, animal suffering, and significant economic losses. 

“Over the past week, USDA has identified and expeditiously confronted four confirmed detections of New World screwworm. While we address these instances that require immediate attention, and continue to sample suspected cases, we are simultaneously working to eradicate the pest entirely,” said Dudley Hoskins, Under Secretary for Marketing and Regulatory Programs. “We need the partnership of animal owners across the region – please stay vigilant, check your animals closely, and report anything that looks suspicious. Together, we can protect our livestock, our communities, and the health of animals nationwide.” 

USDA and the Texas Animal Health Commission (TAHC) continue to lead an aggressive unified response, with a total of 75 people actively responding on the ground and hundreds of additional people around the country providing laboratory diagnostics, logistics, treatment distribution, air operations, outreach, operational planning, and resource support for the response. APHIS and TAHC will continue to surge additional trained personnel as needed to ensure an effective response.  

For each new case, USDA and TAHC implement actions outlined in the NWS Response Playbook, including: 

USDA continues to release sterile flies over and just outside of the infested areas. To ensure sterile fly release operations can be deployed to affected areas in Texas and in northern Mexico near the border as quickly and efficiently as possible, USDA has activated the sterile fly dispersal facility at Moore Air Base in Edinburg, Texas. Sterile pupae arrived at the facility on Friday, and aerial dispersal flights originating from the base will begin tomorrow. 

Because it is important to continue ongoing surveillance efforts while releasing sterile insects, it is possible that sterile NWS flies could be caught and/or reported. To ensure officials can tell the difference between sterile and wild NWS flies, USDA dyes the sterile pupae, and the dye transfers to the sterile flies when they hatch. The fluorescent green or orange dye glows under UV light and may also be visible to the naked eye. If a sterile fly is captured in a trap, this dye allows animal health officials to quickly rule the fly out as a threat.  

USDA urges everyone in the area to check animals for: 

Anyone who suspects a screwworm infestation should immediately contact their veterinarian, state animal health official, or USDA. USDA has established this contact page to ensure everyone can easily find the correct contact information for these groups. In Texas, report suspected cases in livestock directly to TAHC officials by finding your closest area office here.  

Though rare in people, anyone who notices a suspicious lesion should seek immediate medical care. 

The U.S. food supply remains safe. NWS does not infest meat, fruits, vegetables, or other food products. Any affected animal would be identified during USDA Food Safety and Inspection Service inspection, and no contaminated product would enter commerce. 

USDA and its Texas partners are operating with full transparency, committed to keeping producers, veterinarians, local communities, and the public informed as new information becomes available. USDA will continue to provide timely updates and maintain a visible, sustained presence in affected areas. 

More information about New World screwworm is available at Screwworm.gov.