Key Takeaways
- Elanco Animal Health (NYSE: ELAN) has received an Emergency Use Authorization (EUA) from the FDA for Negasunt Powder (coumaphos, propoxur, sulfanilamide topical powder) and a Section 18 Emergency Exemption from the EPA for Tanidil (coumaphos, propoxur), both for the prevention and treatment of New World screwworm infestations in livestock, announced April 27, 2026.
- The authorizations cover cattle, swine, goats, sheep, horses, donkeys, domestic hybrid equids, and captive wild, exotic, and zoo mammals, with confirmed screwworm cases detected as close as 62 miles south of the U.S.-Mexico border.
- Both products will be distributed exclusively through the USDA Animal and Plant Health Inspection Service (APHIS) National Veterinary Stockpile, in coordination with state animal health officials and federally recognized tribal agencies.
- Elanco also offers Catron IV, one of the few EPA-registered products labeled for screwworm treatment across multiple livestock species, along with additional fly and tick control products in pour-on, spray, dust, and ear tag formulations.
- The Section 18 Emergency Exemption for Tanidil is effective April 27, 2026, and expires April 27, 2029; additional requirements for use, including tracking, reporting, and personal protective equipment specifications, will be published by APHIS.
Elanco Receives Emergency Authorizations for Negasunt Powder and Tanidil
Elanco Animal Health Incorporated (NYSE: ELAN) announced on April 27, 2026 that it has received an Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) for Negasunt Powder (coumaphos, propoxur, sulfanilamide topical powder) and a Section 18 Emergency Exemption from the U.S. Environmental Protection Agency (EPA), in cooperation with the U.S. Department of Agriculture (USDA), for Tanidil (coumaphos, propoxur). Both authorizations cover the prevention and treatment of New World screwworm infestations across multiple livestock species, including cattle, swine, goats, sheep, horses, donkeys, domestic hybrid equids, and captive wild, exotic, and zoo mammals.
The authorizations follow confirmed detection of New World screwworm as close as 62 miles south of the U.S.-Mexico border, providing veterinarians and livestock producers with treatment options ahead of potential entry of the fly into the United States.
“We appreciate our federal agencies’ swift review of the scientific data demonstrating that these products may be effective in prevention and treatment against New World screwworm infestations. We’re committed to working alongside state and federal regulatory authorities to provide our support and scientific expertise. These emergency authorizations provide new, science-based solutions and treatment options to livestock producers, veterinarians, and other animal health industry stakeholders at a time when they need them most,” said Dr. Ellen de Brabander, Executive Vice President of Research & Development at Elanco.
Distribution and Access Restrictions
Both Negasunt Powder and Tanidil will be available exclusively through the USDA APHIS National Veterinary Stockpile and distributed in coordination with state animal health officials and federally recognized tribal agencies. APHIS has indicated it will release additional guidance on requirements for use, including tracking and reporting requirements and required personal protective equipment. Negasunt Powder is authorized under the EUA until the declaration justifying its emergency use is terminated or revoked.
Elanco Veterinarians Outline Key Prevention Protocols
Dr. M. Wayne Ayers, Senior Technical Consultant and veterinarian at Elanco, said frequent livestock monitoring and early wound detection were critical to limiting infestations and preventing spread.
“The most important thing producers can do is self-education. They should be learning more about New World screwworm from credible sources, staying current with treatment protocol recommendations, and knowing where active cases are located. Looking over livestock as frequently as possible will allow early detection and treatment of infestation. Early intervention is key to minimizing tissue damage, decreasing mortality, and reducing the risk to the area by preventing the fly’s potential offspring from completing their lifecycle,” said Dr. M. Wayne Ayers, Senior Technical Consultant and veterinarian at Elanco.
Dr. Ayers also noted that wounds caused by other parasites, including biting flies and ticks, can serve as entry points for New World screwworm and that a comprehensive fly and tick control program is an important component of prevention.
Additional Parasite Control Products and Resources
In addition to the newly authorized products, Elanco offers Catron IV, described as one of the few EPA-registered products labeled for screwworm treatment across beef and dairy cattle, sheep, goats, hogs, and horses. The company also provides EPA-registered fly and tick control products in pour-on liquid, spray, dust, and ear tag formulations. Elanco recommends that livestock producers and veterinarians consult the latest resources published by the USDA and FDA for current New World screwworm prevention and treatment protocols.
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