New World Screwworm Confirmed in Texas and New Mexico, Prompting Emergency Measures

The U.S. Department of Agriculture has confirmed five cases of the New World screwworm in the United States. Two calves in Zavala County, Texas, a third calf in La Salle County, and a dog in Andrews County were the first four cases. A fifth case was identified in a dog from Lea County, New Mexico, marking the parasite’s first confirmed presence in that state.

State and federal officials have declared local disasters in several Texas counties and issued a statewide disaster proclamation. Governors and agriculture commissioners in Texas, Florida, Louisiana, Arkansas and New Mexico have introduced emergency rules restricting the movement of warm‑blooded animals from exposed zones. The USDA is deploying millions of sterile screwworm flies each week and plans a $750 million factory in Texas to boost production, aiming to halt the pest’s spread.

Economists warn the outbreak could jeopardize the U.S. cattle herd, which already faces record‑high beef prices and a multi‑year downcycle, potentially costing the Texas cattle economy up to $1.8 billion. Canada has temporarily halted imports of cattle and other livestock from Texas. The response includes intensified surveillance, veterinary inspections and public outreach to animal owners across the region.