Washington, DC – The U.S. Food and Drug Administration has issued an Emergency Use Authorization for a generic over-the-counter medication to treat New World screwworm infestations in dogs and cats, marking the first generic animal drug approved for use against the pest.
According to the FDA, Nitenpyram Tablets can now be used to treat New World screwworm (NWS) infestations, known as myiasis, in dogs, puppies, cats and kittens that are at least four weeks old and weigh at least two pounds.
Federal officials emphasized that most pets in the United States remain at low risk for NWS. However, risk may be higher for animals that have recently traveled through or lived in areas where confirmed screwworm cases have been identified.
New World screwworm flies lay eggs in open wounds or mucous membranes of mammals. Once hatched, larvae burrow into living tissue, causing severe injury if left untreated.
The FDA said Nitenpyram acts quickly, killing most larvae within hours of administration. Pet owners are advised to administer a second dose six hours after the first treatment. Because the medication’s effects are short-lived, it does not prevent future infestations or reinfestation.
“The FDA has spent nearly a year fast-tracking reviews and readying for the arrival of New World screwworm in the U.S.,” Acting FDA Commissioner Kyle Diamantas said in a statement.
Veterinary professionals may still need to remove dead or surviving larvae after treatment and provide additional wound care to reduce the risk of infection and further tissue damage.
Nitenpyram Tablets are available without a prescription in two dosage strengths: 11.4 milligrams and 57 milligrams. Dosage depends on the animal’s weight, and the product should not be given to pets weighing less than two pounds.
The authorization is part of a broader federal response to prevent and contain the spread of New World screwworm in the United States. Officials said the FDA has now issued multiple emergency authorizations and conditional approvals related to NWS prevention and treatment efforts.
