Elanco Receives Emergency Authorizations for Negasunt Powder and Tanidil to Treat New World Screwworm in Livestock

Key Takeaways

• Negasunt Powder and Tanidil receive FDA EUA and EPA Section 18 exemption
• Authorization covers cattle, swine, goats, sheep, horses, and exotic mammals
• Products will be distributed exclusively via USDA APHIS National Veterinary Stockpile
• Elanco also markets Catron IV, a registered screwworm treatment for multiple species
• Emergency use expires April 27, 2029, with tracking and PPE requirements

Pulse Analysis

The New World screwworm, a parasitic fly that can devastate livestock, has resurfaced near the U.S.–Mexico border, prompting heightened bio‑security alerts. Historically responsible for severe economic damage in the Americas, the fly’s larvae burrow into wounds, causing tissue loss, secondary infections, and high mortality rates. Early detection and rapid treatment are critical, as the insect’s life cycle can complete within weeks, allowing swift spread across herds and farms. Federal agencies have therefore prioritized containment measures to safeguard the nation’s $200 billion livestock industry.

Elanco’s dual emergency clearances represent a rare convergence of FDA and EPA actions. The FDA’s Emergency Use Authorization for Negasunt Powder validates its safety and efficacy for immediate deployment, while the EPA’s Section 18 exemption permits Tanidil’s use despite its standard registration constraints. Both products combine coumaphos and propoxur, insecticides with proven activity against dipteran larvae, and are now accessible through the USDA APHIS National Veterinary Stockpile. By channeling distribution through a centralized stockpile, regulators ensure controlled dispensing, traceability, and compliance with reporting and personal‑protective‑equipment mandates, mitigating misuse and environmental concerns.

Beyond the immediate response, the authorizations signal broader market and policy implications. Livestock producers now have FDA‑approved tools to address a threat that previously relied on off‑label or experimental treatments, potentially reducing mortality and preserving export eligibility. The episode also underscores the importance of coordinated federal‑state‑tribal frameworks for rapid disease‑vector interventions. As climate patterns shift, similar emergent pests may test existing regulatory pathways, positioning companies like Elanco to leverage their diversified parasitic‑control portfolios for future bio‑security challenges.