FDA Authorizes Nitenpyram to Prevent New World Screwworm in Pets

The FDA has issued an Emergency Use Authorization covering Capstar (nitenpyram) tablets and revised an existing authorization for generic Nitenpyram Tablets, allowing both products to be used for prevention as well as treatment of New World screwworm infestations in dogs, puppies, cats, and kittens, according to an FDA press announcement. Nitenpyram Tablets were first authorized in June 2026 for treatment only, so this update fills what the agency's Center for Veterinary Medicine director called a previously unmet need for a preventive option.

The authorization applies to animals weighing at least two pounds and at least four weeks old. Most pets in the United States remain at low risk because confirmed screwworm cases are limited to specific regions, but animals that live in, travel to, or return from affected areas should be watched closely for signs of infestation, including visible maggots or foul odor around wounds or body openings. The FDA says infested animals need immediate veterinary care.

This is an Emergency Use Authorization for an animal drug, not a peptide, and not a human medication. It remains in effect until revoked or until the underlying public health emergency declaration ends.

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