Emergency authorization expands access to preventive tools against New World screwworm as cross-border risks rise

Boehringer Ingelheim has received an Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) for IVOMEC (ivermectin) 1 per cent Injection to prevent infestations caused by New World screwworm (Cochliomyia hominivorax) in cattle. The authorization marks the first FDA-issued EUA for an over-the-counter product intended to prevent New World screwworm infestations in cattle.

Under the EUA, IVOMEC (ivermectin) 1 per cent Injection is authorized for preventive use at critical intervention points, including within 24 hours of birth, at the time of castration, or upon the appearance of a wound in cattle. The authorization excludes female dairy cattle producing milk for human consumption and calves intended for veal production. The FDA determined that no adequate, approved, and available alternatives currently exist for preventing New World screwworm infestations in cattle at these stages.

The decision comes amid ongoing detections of New World screwworm in livestock in northern Mexico, including the border state of Tamaulipas, heightening concerns around potential cross-border spread and reinforcing the need for U.S. preparedness. While the parasite is not currently present in the United States, federal authorities have emphasized early access to preventive tools as a key component of national livestock biosecurity.

New World screwworm is a parasitic fly whose larvae feed on living tissue, causing severe wounds, secondary infections, and potentially fatal outcomes in affected animals. Infestations often occur when cattle are most vulnerable, including during calving and following routine husbandry procedures that create open wounds.

The EUA enables broader access to IVOMEC (ivermectin) 1 per cent Injection as part of coordinated federal and industry preparedness efforts involving the FDA, USDA, and state animal health authorities. The authorization remains valid only for the duration of the declared emergency under Section 564 of the Federal Food, Drug, and Cosmetic Act, unless terminated or revoked earlier.

The approval underscores the role of emergency regulatory mechanisms in safeguarding animal health, food security, and producer livelihoods, particularly in response to emerging transboundary animal health threats.