FDA Issues Emergency Use Authorization for Drugs to Prevent and Treat New World Screwworm in Dogs and Cats

Silver Spring, Md, Sept. 03, 2026 (GLOBE NEWSWIRE) — The U.S. Food and Drug Administration today issued an Emergency Use Authorization (EUA) for Capstar (nitenpyram) tablets and revised the EUA for Nitenpyram Tablets, the generic version of Capstar, to authorize both products for the prevention and treatment of New World screwworm (NWS) infestations (myiasis) in dogs, puppies, cats, and kittens that weigh at least two pounds and are at least four weeks old. Nitenpyram Tablets were initially authorized in June 2026 for treatment only.

“Although the FDA has authorized or conditionally approved multiple products for the treatment of New World screwworm in dogs and cats, none were for prevention – until today,” said Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine. “The FDA is addressing a previously unmet need and giving pet owners and veterinarians important tools to protect dogs and cats from NWS infestations.”

Currently, most dogs and cats in the U.S. are at low risk of NWS exposure because confirmed cases of NWS are in a limited geographic region. However, 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, such as visible maggots or foul odors in wounds or body openings (e.g., eyes, ears, nose, mouth). Seek immediate veterinary care for infested dogs and cats. For up-to-date U.S. case information, see the U.S. Department of Agriculture’s dashboard of Confirmed Detections of New World Screwworm.

Based on the totality of the scientific evidence available, the FDA has concluded it is reasonable to believe 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, and the known and potential benefits of the products outweigh their known and potential risks.

Capstar and Nitenpyram Tablets are available over the counter and come in two tablet sizes: 11.4 and 57 mg. Dosage is based on a dog’s or cat’s weight. Do not administer to pets less than two pounds or younger than four weeks old.

For detailed information about how to use these products, pet owners should carefully review the relevant product’s fact sheet. All EUA product Fact Sheets, FOI Summaries, and Letters of Authorization are available on Emergency Use Authorization of Animal Drugs for NWS.

These EUAs will be 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.

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.

Related Information 

Animal Drugs for New World Screwworm
Emergency Use Authorization of Animal Drugs for NWS
Screwworm.gov – Unified Government Response to Protect the United States

Media: FDA Request for Comment 

Consumer: 888-INFO-FDA

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The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, radiation-emitting electronic products, and for regulating tobacco products.

Contact Info

U.S. Food and Drug Administration
FDAPressAlerts@fda.hhs.gov
+1 202-690-6343


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