FDA Issues Emergency Use Authorizations for Two Drugs to Combat New World Screwworm

On May 19, 2026, the U.S. Food and Drug Administration issued an Emergency Use Authorization (EUA) for Dectomax/Dectomax-CA1 (doramectin injection) injectable solution for the prevention and treatment of New World screwworm (NWS) infestations (myiasis) in dairy cattle (lactating dairy cows, dry dairy cows, and replacement dairy heifers 20 months of age and older), except for calves that will be processed for veal. The EUA also authorizes Dectomax/Dectomax-CA1 for the prevention of NWS myiasis in swine, horses at least one year old, sheep except for lactating sheep, and deer.

The FDA also issued an EUA for CLiK Extra (dicyclanil topical suspension) wound spray for application on or around wounds for the prevention of NWS infestations in sheep, cattle, goats, swine, camelids (e.g., camels, llamas, alpacas), and the following captive and captured wildlife species: cervids (e.g., deer, elk), American bison, bighorn sheep, and Sonoran pronghorn. Based on the totality of the scientific evidence available, the FDA has concluded it is reasonable to believe that CLiK Extra wound spray may be effective in the prevention of NWS myiasis when used as authorized, and the known and potential benefits of the product outweigh its known and potential risks.

This EUA authorizes CLiK Extra wound spray only for prevention of NWS myiasis associated with wounds, birth, and after surgical or husbandry procedures (e.g., dehorning, ear tagging, castration, tail docking, shearing). It is applied at the time of wound appearance or creation. If a wound is already infested, or if an infestation develops after administering the product, contact a veterinarian to discuss treatment options. CLiK Extra wound spray is available over the counter for topical use. Rather than killing NWS larvae, it acts as an insect growth regulator that disrupts the development of larvae and halts their lifecycle before they can cause tissue damage in the host animal. CLiK Extra wound spray is not approved or conditionally approved by the FDA for any indication.

The acting FDA commissioner stated that under President Trump’s leadership, American farmers, ranchers, veterinarians, and wildlife managers are being given the tools they need to fight back, and that today's emergency use authorization provides a new tool for preventing the spread of NWS infestations. The director of the FDA’s Center for Veterinary Medicine said the FDA recognizes that the impact of NWS extends beyond the farm gate, and authorizing the product for captive and captured wildlife species is about protecting these animals and helping ensure they do not contribute to the spread of NWS in the United States. This EUA will be effective until it is revoked or the HHS Secretary terminates the declaration that the potential public health emergency presented by NWS justifies the emergency use authorization of animal drugs for NWS.