FDA Issues Emergency Use Authorizations for NexGard Products to Treat Screwworm in Pets

The U.S. Food and Drug Administration issued two Emergency Use Authorizations (EUAs) on February 18, 2026 – one for NexGard (afoxolaner) chewable tablets for the treatment of New World screwworm (NWS) infestations (myiasis) in dogs, and the second for NexGard COMBO (esafoxolaner, eprinomectin, and praziquantel topical solution) for the treatment of NWS myiasis in cats.

For NexGard, the agency has concluded that based on the scientific evidence available, it is reasonable to believe that NexGard may be effective in the treatment of NWS myiasis in dogs and puppies, and the known and potential benefits of the product outweigh its known and potential risks.

For NexGard COMBO, the agency has concluded that based on the scientific evidence available, it is reasonable to believe that NexGard COMBO may be effective in the treatment of NWS myiasis in cats and kittens, and the known and potential benefits of the product outweigh its known and potential risks.

These EUAs will be effective 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.

As of February 18, 2026, NWS has not been detected in the United States. Most dogs and cats in America are at low risk of NWS due to their geographic location; however, pets near the U.S.-Mexico border and pets that have traveled to countries with active NWS cases are more likely to be exposed to NWS.

NexGard and NexGard COMBO are available only by prescription from a licensed veterinarian because professional expertise is required to monitor for and respond to potential adverse reactions.

Afoxolaner, the active ingredient in NexGard, and esafoxolaner, one of the active ingredients in NexGard Combo, belong to a class of antiparasitic drugs called isoxazolines. Although isoxazoline products are commonly used and safe for most pets, the products have been associated with neurologic adverse reactions, including muscle tremors, ataxia, and seizures. Pet owners should consult with a veterinarian to determine whether NexGard or NexGard Combo may be appropriate for their pet.

In addition to the EUA, NexGard chewable tablets are FDA-approved for flea and tick-related indications in dogs and puppies. NexGard COMBO topical solution is FDA-approved for flea, tick, and worm-related indications in cats and kittens.

NexGard and NexGard COMBO are sponsored by Boehringer Ingelheim Animal Health USA, Inc. based in Duluth, Georgia.