FDA grants EUA to F10 spray for New World screwworm

CURRENT BRIEF VERSION: The FDA has issued an Emergency Use Authorization for F10 Antiseptic Wound Spray with Insecticide for the prevention and treatment of New World screwworm myiasis in cattle, horses, minor species of hoof stock, raptors and other wild birds, pet birds, and captive wild, exotic, and zoo mammals. The spray contains benzalkonium chloride, polyhexanide, and cypermethrin, and it expands access to a product that had already been indexed since 2015 for wound antisepsis, fly repellency, and fly strike treatment in certain minor species, but not for New World screwworm. The authorization follows HHS’s August 18, 2025 declaration enabling FDA to issue animal-drug EUAs for screwworm as the parasite continued moving north toward the U.S. border. That broader response now also includes other treatment pathways, including an FDA EUA for over-the-counter Ivomec (ivermectin) injectable solution to help prevent screwworm in cattle and an EPA emergency exemption allowing USDA to import Tanidil from Brazil for the national veterinary stockpile. (fda.gov)

Why it matters: For veterinarians, this adds an over-the-counter topical option for a broad mix of species that may be exposed during a screwworm response, including livestock, equids, birds, and zoo or exotic mammals. The authorization also comes with practical guardrails: cattle, goats, and sheep carry a 30-day slaughter withdrawal and 10-day milk discard period, the product must not be used in dogs or cats, and it should be used only as directed under the EUA fact sheet. That species breadth matters because FDA has said a diverse supply of products will be needed if the U.S. faces an incursion, and APHIS continues to emphasize rapid reporting and coordinated response for suspected cases. The wider toolkit is also becoming more defined: Ivomec is positioned for cattle wound-risk moments such as birth or castration, while Tanidil is being staged through APHIS for livestock, some wildlife, and select zoo species rather than pets or birds. (fda.gov)

What to watch: Watch for additional FDA authorizations, state-level response planning, and any change in APHIS’s screwworm status updates as federal agencies continue to build out the treatment toolbox. One practical issue to follow is Tanidil’s rollout timeline: APHIS has said importation and relabeling could take roughly 90 to 100 days, and some states may require their own pesticide registration before use. (fda.gov)