In a significant regulatory shift aimed at safeguarding animal health and the agricultural economy, the U.S. Department of Health and Human Services declared on August 18, 2025, that the Food and Drug Administration may now issue Emergency Use Authorizations (EUAs) for animal drugs to treat or prevent infestations of the New World screwworm (Cochliomyia hominivorax). While this parasite has been eradicated from the U.S. for decades, recent reports in Mexico indicate a renewed threat across the southern border

What This Emergency Action Means
Under the newly declared emergency, the FDA can authorize unapproved drugs-or approved drugs being used for unapproved purposes-for screwworm control, offering veterinary and livestock operators a faster path to treatment amid a crisis. The agency is conducting reviews of existing literature and foreign markets to identify suitable alternatives, with groups like R-CALF USA urging broader access to drugs like ivermectin as a proactive measure.

Why the Move Is Critical
The parasite's danger is ominous-even if the current human health risk remains low, its appetite for warm-blooded animals, including cattle, pets, and wildlife, could devastate livestock yields and the food supply chain. The USDA has already halted imports of Mexican cattle and is coordinating accelerated animal drug access to stem any incursion.

Sterile Fly Strategy & Infrastructure Investments
While long-term control still relies on the sterile insect technique, its implementation requires massive insect output. Accordingly, the USDA has proposed a $750 million facility in Texas to produce sterile screwworm flies-expected to take up to three years to come online-but EUAs offer a vital stopgap during this ramp-up phase.

Regulatory Underpinnings
On August 18, HHS Secretary Robert F. Kennedy, Jr. invoked section 564 of the Federal Food, Drug, and Cosmetic Act to justify the emergency declaration, providing legal grounds for expedited drug access. The FDA's Center for Veterinary Medicine (CVM) is coordinating with USDA and the EPA to streamline pathways such as conditional approvals, extra-label use, and emergency use authorization tailored to the immediate screwworm threat.

Voices from the Frontline
"Our priority is to safeguard both animal health and the nation's food supply," said FDA Commissioner Marty Makary, M.D., M.P.H. Adding urgency to the declaration, HHS Secretary Kennedy remarked that the action "equips FDA to act quickly, limit the spread... and protect America's livestock". Agriculture Secretary Brooke L. Rollins emphasized the stakes as "a national security priority," reflecting mounting pressure from ranchers expecting rapid government action.

Bottom Line for Stakeholders

• Veterinarians and livestock producers now have a new regulatory channel to legally access drugs for screwworm control, even if they lack U.S. approval for that use.

• Animal drug sponsors are invited to seek emergency authorizations, with FDA requesting data to evaluate eligibility.

• In the interim, ranchers remain on high alert, monitoring livestock closely while awaiting both medical tools and sterile-fly facilities to become operational.

The return of the New World screwworm presents a deep challenge-not just for agriculture but for supply chains and economic stability. Yet with this emergency authorization, the U.S. is showing capacity for quick, precautionary defense against a potential agricultural calamity.