FDA Authorized an OTC Treatment for New World Screwworm in Pets — Here's How to Use Nitenpyram if Your Dog or Cat Is Infested

A flesh-eating parasitic fly has established itself in southern Texas and New Mexico, and the federal government's response now spans three agencies, a Level 3 emergency declaration, and the first-ever FDA-authorized over-the-counter treatment for the parasite in domestic pets.

The U.S. Centers for Disease Control and Prevention's Level 3 Emergency Operations Center remains active as of June 16–17, 2026, coordinating the response alongside the U.S. Department of Agriculture, Texas health and agriculture officials, and the Food and Drug Administration. According to HealthDay reporting confirmed June 16, 2026, 12 cases of New World screwworm (NWS) have been confirmed in domestic animals — including sheep, cattle, and goats — in southern Texas and one county in New Mexico, with the USDA conducting aerial releases of sterile insects as the primary biological containment strategy.