FDA Authorizes Capstar for Prevention of New World Screwworm in Dogs and Cats

Silver Spring, Md, Sept. 03, 2026 /CourierPR/ -- The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for Capstar (nitenpyram) tablets and revised the EUA for Nitenpyram Tablets, the generic version of Capstar, to allow both products for the prevention and treatment of New World screwworm (NWS) infestations in dogs, puppies, cats, and kittens that weigh at least two pounds and are at least four weeks old. This authorization marks a significant step in addressing a previously unmet need for pet owners and veterinarians to protect dogs and cats from NWS infestations.

Capstar and Nitenpyram Tablets were initially authorized in June 2026 for treatment only. The new EUA broadens their use to include prevention, making them valuable tools for pet owners and veterinary professionals.

Currently, most dogs and cats in the U.S. are at low risk of NWS exposure because confirmed cases are limited to a specific geographic region. However, pet owners and veterinarians should remain vigilant. Dogs and cats that live in, travel to, or return from areas where NWS infestations have been identified by state or federal animal health officials, as well as certain countries south of the U.S. border, should be closely monitored for signs of infestation. These signs include visible maggots or foul odors in wounds or body openings, such as the eyes, ears, nose, or mouth. Immediate veterinary care is recommended for infested dogs and cats.

The FDA based its decision on the totality of the scientific evidence available, concluding that Capstar and Nitenpyram Tablets may be effective in the prevention and treatment of NWS myiasis in certain dogs, puppies, cats, and kittens when used as authorized. The known and potential benefits of the products outweigh their known and potential risks.

Capstar is sponsored by Sergeant’s Pet Care Products LLC of Omaha, Nebraska, and Nitenpyram Tablets are sponsored by Felix Pharmaceuticals Pvt. Ltd. based in Ireland. The EUAs will remain in effect until they are 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.

For detailed information on how to use these products, pet owners should carefully review the relevant product’s fact sheet. The FDA encourages pet owners to stay informed about the latest developments in NWS prevention and treatment through its resources, including the U.S. Department of Agriculture’s dashboard of confirmed NWS detections.

This new authorization is part of the broader effort to protect pets from the New World screwworm, a parasitic fly that can cause severe infestations leading to significant health risks for animals. The FDA’s action underscores its commitment to safeguarding the health and well-being of pets and their owners.