On Jun. 11, 2026, The U.S. Food and Drug Administration issued an Emergency Use Authorization (EUA) for generic Nitenpyram Tablets (nitenpyram) for the 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. This is the first generic animal drug authorized for use against NWS.

The FDA has concluded that based on the totality of the scientific evidence available, it is reasonable to believe that Nitenpyram Tablets may be effective in the treatment of NWS myiasis in certain dogs, puppies, cats, and kittens, and the known and potential benefits of the product outweigh its known and potential risks.

NWS flies lay eggs in open wounds or mucous membranes of mammals and the larvae hatch within hours and burrow into the animal’s flesh. Nitenpyram works quickly, killing most NWS larvae within hours of the first dose. Pet owners should administer a second dose six hours after the first. Because the effects are short-acting, Nitenpyram Tablets do not prevent NWS myiasis or protect against reinfestation.

Following treatment with Nitenpyram Tablets, a veterinary professional may need to physically remove any remaining live or dead larvae. This task is best performed by someone with training in veterinary medicine to minimize the risk of infection or further tissue damage. Pet owners should consult a veterinarian about appropriate wound care and how to minimize the risk of reinfestation.

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. Nitenpyram Tablets are produced by Felix Pharmaceuticals based in Ireland.