- The FDA has issued Emergency Use Authorizations (EUAs) for NexGard® (afoxolaner) in dogs and NexGard® COMBO (esafoxolaner, eprinomectin, praziquantel) in cats to treat New World screwworm (NWS) infestations.
- The action comes as NWS cases are confirmed in northern Mexico, prompting heightened U.S. preparedness efforts.
- Both products are available only through licensed veterinarians and are temporarily authorized under federal emergency provisions.
The U.S. Food and Drug Administration has granted Emergency Use Authorizations (EUAs) for two Boehringer Ingelheim parasiticides—NexGard® (afoxolaner) Chewables for dogs and puppies, and NexGard® COMBO (esafoxolaner, eprinomectin, and praziquantel topical solution) for cats and kittens—for the treatment of infestations caused by New World screwworm (Cochliomyia hominivorax).
While New World screwworm is not currently present in the United States, recent confirmations in livestock in northern Mexico, including in Tamaulipas, a state bordering Texas, have increased vigilance among animal health officials. The authorizations are intended to ensure veterinarians have treatment options readily available should cases emerge in companion animals.
Addressing a High-Consequence Parasite
New World screwworm is a parasitic fly that lays eggs in open wounds or soft tissue of warm-blooded animals. After hatching, larvae burrow into living tissue, causing rapid and potentially fatal damage. Animals that have recently given birth, undergone surgery, or sustained wounds are considered particularly vulnerable.
According to Boehringer Ingelheim, rapid access to authorized treatment options is critical because infestations can escalate quickly, and treatment delays may significantly worsen outcomes. The company also emphasized that routine flea and tick prevention remains important to help minimize skin irritation and small bite-related wounds that could provide sites for flies to lay eggs.
Temporary Emergency Authorization
NexGard and NexGard COMBO have not been fully approved for treatment of New World screwworm. Their use is authorized under Section 564(b)(1) of the Federal Food, Drug, and Cosmetic Act for the duration of the declared emergency circumstances, unless the authorization is terminated or revoked sooner.
NexGard (afoxolaner) is labeled for use in dogs and puppies 8 weeks of age or older, weighing at least 4 pounds. Reported adverse reactions include vomiting, itching, lethargy, diarrhea, and decreased appetite. Use with caution in dogs with a history of seizures or neurologic disorders.
NexGard COMBO (esafoxolaner, eprinomectin, and praziquantel topical solution) is for topical use in cats and kittens 8 weeks of age or older, weighing at least 1.8 pounds. Reported adverse reactions include vomiting, application-site reactions, lethargy, and anorexia. Use with caution in cats with a history of seizures or neurologic disorders.
Information sourced from the company’s press release.
