FDA Grants Emergency Use Authorization for Generic Ivermectin Injection to Prevent New World Screwworm in Cattle

On August 27, 2026, the U.S. Food and Drug Administration issued an Emergency Use Authorization (EUA) for Bimectin (ivermectin) injection, a generic version of Ivomec, for the prevention of New World screwworm (NWS) myiasis in cattle. The authorization covers administration within 24 hours of birth, at castration, or upon appearance of a wound, but excludes lactating dairy cows and calves destined for veal. This marks the FDA's 14th EUA related to NWS countermeasures.

Bimectin, sponsored by Bimeda Animal Health, builds on the February 2026 EUA for Ivomec (ivermectin) injectable solution from Boehringer Ingelheim. The decision relies on studies from Brazil and Argentina in the 1990s, plus a 2019 Brazilian study, alongside the drug's established safety profile for cattle and food safety for human consumption with a 35-day slaughter withdrawal. FDA officials noted that benefits outweigh risks and emphasized expanding generic options to reduce reliance on single manufacturers.

The authorization occurs amid a 2026 NWS incursion into the U.S. from Mexico, with USDA reporting three cases in Texas through August 25 (two in sheep, one in a goat), following 14 in July and 30 in June. The Trump administration has approved or authorized over a dozen NWS-related animal drugs, including treatments for dogs, cats, horses, and other species, reflecting a coordinated federal response involving the FDA, USDA, and partners to protect agriculture and public health.

This move highlights ivermectin's established role as an antiparasitic while addressing supply resilience for livestock producers facing an emerging pest threat not seen in the U.S. in years.