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, authorizing the over-the-counter topical product for 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 March 10, 2026 authorization expands the product beyond its earlier indexed minor-species wound and fly-strike uses, and comes as federal agencies continue building out a broader New World screwworm response. The EUA does not cover domestic dogs or cats, and it carries specific food-safety restrictions, including a 30-day slaughter withdrawal for cattle, goats, and sheep, plus a 10-day milk discard period for cows, goats, and sheep. (fda.gov)

Why it matters: For veterinarians, this adds a multi-species option at a time when New World screwworm preparedness is moving from policy to practice. The FDA says F10 may help both prevent infestation when applied to wounds and treat active myiasis, while also providing antiseptic coverage. That matters especially for mixed-animal, equine, avian, wildlife, exotic, and zoo practices that have had fewer labeled tools than cattle medicine, where products such as doramectin and the over-the-counter injectable Ivomec (ivermectin) have already moved through conditional approval or EUA pathways. Ivomec’s cattle EUA covers preventive use when given within 24 hours of birth, at castration, or when a wound appears, but it also comes with its own limits, including no use in female dairy cattle producing milk for human consumption, no veal use, and a 35-day slaughter withdrawal. The catch with F10 is operational: extralabel use is not permitted under this EUA, so species limits, residue precautions, and veal and horse restrictions need to be followed closely. Producers and veterinary teams are also being urged to use antiparasitics only when medically necessary and as part of a broader parasite-management strategy to help limit resistance pressure. (fda.gov)

What to watch: Watch for additional FDA authorizations, field-use guidance, and surveillance updates as the U.S. response to screwworm pressure near the southern border continues to expand. As more products come online under emergency mechanisms, expect closer attention to species-specific directions, withdrawal times, and stewardship messaging. (fda.gov)