The U.S. Food and Drug Administration has updated its guidance for veterinarians on New World screwworm, a parasite that can cause myiasis in animals. The agency says its Center for Veterinary Medicine is working with animal drug sponsors to identify potential products and seek approval or other authorization pathways for prevention and treatment.
For veterinarians, the update mainly clarifies what is legally available now and which regulatory route applies to each option. The FDA also says it will update the page as new information becomes available, making it an active reference point for animal health professionals.
What the FDA says is currently available?
The FDA page lists conditionally approved animal drugs for New World screwworm in cattle and dogs. These include Dectomax-CA1 for prevention and treatment in cattle, Exzolt Cattle-CA1 for prevention and treatment in cattle, and Credelio Quattro-CA1 for treatment in dogs and puppies.
The agency explains that this list may grow as more products move through the review process. Veterinarians can review the main federal guidance here FDA New World screwworm information for veterinarians.
Emergency authorization pathway remains available
The FDA says the Department of Health and Human Services issued a declaration on August 18, 2025, enabling the agency to issue Emergency Use Authorizations for animal drugs intended to treat or prevent New World screwworm infestations. This gives regulators another route to expand access when needed.
The current FDA page includes emergency-authorized products for dogs, cats, cattle, horses, birds, and other species. Among the listed products are Credelio, Credelio CAT, Ivomec, NexGard, NexGard COMBO, and F10 Antiseptic Wound Spray with Insecticide. More on that process is available through the FDA summary of the EUA issuance process.
Why extralabel use still matters for veterinarians?
The FDA also reminds veterinarians that extralabel use is allowed only under existing regulations and within a valid veterinarian-client-patient relationship. That can matter when a clinician is considering how to use an FDA-approved product outside the exact wording of its label.
At the same time, the agency makes clear that extralabel use is limited to drugs with full FDA approval. It does not include conditional approvals, index listed products, or products used under an emergency use authorization. The legal framework is available in 21 CFR Part 530.
What veterinarians may watch next?
The FDA page functions as a working resource rather than a single announcement. It also links to additional material on animal drug regulation, approval, conditional approval, and a veterinarian FAQ on animal drugs related to New World screwworm.
For broader industry context, related coverage can be found at Agroinformacion. The official guidance was published on the U.S. Food and Drug Administration website.