Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality (SENASICA) confirmed a positive detection of New World screwworm (NWS) in Montemorelos, Nuevo Leon, Mexico.
Please see the following information currently available related to the detection:
According to USDA Animal and Plant Health Inspection Service (APHIS), this case is located less than 120 miles from the U.S.-Mexico border.
- The NWS detection was found in a 22-month-old bovine transported from Veracruz to a Nuevo León feed lot and is the only affected animal in the shipment.
- There were no additional detections related to October 2025 case.
Key messages and resources for producers include:
- Livestock producers, especially those located on the southern border, should check their animals often and keep a close eye on clinical signs consistent with NWS.
- Finding single cases like this in Mexico proves the effectiveness of diligent surveillance and the importance of early detection for stopping the spread of this pest.
- Travelers from NWS-affected areas should closely monitor animals for signs and promptly report suspected cases of NWS.
- If you suspect NWS, do not move the animal and call the TAHC or your veterinarian immediately.
EWA remains engaged through weekly NWS coordination calls and will continue providing timely updates. If you have any questions please contact the EWA office at (830) 315-7761