Overview
- The latest detection involved a goat in the State of Mexico that was treated, with 20 other animals at the site testing negative and receiving preventive care.
- A separate case on Dec. 31 was confirmed in a 6-day-old calf in Tamaulipas, the only positive animal on site as authorities stepped up local safeguards.
- Government data show 13,106 cases since November 2024, including 671 active as of Dec. 31, with most reported in Chiapas, Oaxaca, Veracruz and Yucatán.
- The United States has kept the border largely closed to Mexican livestock since May 2025, and officials say the pest has not breached U.S. herds.
- Screwworms are parasitic flies that can be lethal to animals if untreated, and the USDA estimates potential losses of about $1.8 billion to Texas alone.