New World screwworm guidance from the FDA now gives veterinarians a clearer picture of which animal drugs are available and which legal pathway applies to each one. The agency says its Center for Veterinary Medicine is working with animal drug sponsors to identify products and move them through approval or other authorization routes for the prevention or treatment of New World screwworm myiasis.
The update matters because the FDA page is designed as a working reference for veterinarians, not a one-time notice. It says the page will be updated as new information becomes available. That means vets, livestock producers, and animal health professionals may need to keep checking for changes as more products move through the system.
New World screwworm guidance now lists conditional approvals
The FDA says three animal drugs are currently listed as approved or conditionally approved for New World screwworm. Those are Dectomax-CA1 for cattle, Exzolt Cattle-CA1 for cattle, and Credelio Quattro-CA1 for dogs and puppies. The listed indications cover prevention, treatment, or both, depending on the product.
The agency also notes that the table will be updated as more drugs are approved or conditionally approved for this use. Veterinarians who want to review the full federal page can find it here FDA New World Screwworm information for veterinarians. That same page also links to background material on animal drug approval and conditional approval.
Emergency use authorizations expand the available options
The FDA says the Department of Health and Human Services issued a declaration on August 18, 2025, that enables the agency to issue Emergency Use Authorizations for animal drugs to treat or prevent infestations caused by New World screwworm. This gives regulators another path to make products available while the threat remains a concern.
On the current FDA list, emergency-authorized products include Credelio for dogs, Credelio CAT for cats, Ivomec for certain cattle uses, NexGard for dogs, NexGard COMBO for cats, and F10 Antiseptic Wound Spray with Insecticide for several species. The FDA overview of that process is available here Summary of Process for EUA Issuance.
Extralabel use rules still matter for veterinarians
The FDA also reminds veterinarians that extralabel use can be allowed under existing regulations and within a valid veterinarian client patient relationship. That matters when a vet is considering how to use an FDA approved product beyond the exact wording on the label in a real clinical setting.
At the same time, the agency makes an important distinction. It says extralabel use is limited to drugs with full FDA approval. It does not include conditional approvals, index listed products, or products being used under an emergency use authorization. The federal rule the agency points to is 21 CFR Part 530.
What veterinarians may watch next?
The updated page also points readers to a separate veterinarian FAQ on animal drugs related to New World screwworm. That suggests the FDA expects practical questions from the field as vets work through treatment decisions for cattle, pets, horses, birds, zoo animals, and other species covered by the current listings.
For broader sector context, related coverage is available at Agroinformacion. The official guidance was published on the U.S. Food and Drug Administration website.