New emergency authorization offers producers another cattle health tool
The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for Bimectin (ivermectin) injection to help prevent New World screwworm infestations in cattle.
The authorization allows producers to use the product within 24 hours of birth, during castration, or when a wound appears. The move is intended to support efforts to protect cattle from damaging parasites, which can cause serious health problems in livestock.
According to the FDA, Bimectin is a generic version of Ivomec, a product that received authorization earlier in 2026 for the same purpose. The agency said offering both generic and pioneer products provides producers with more choices and reduces reliance on a single manufacturer.
“This authorization reflects the FDA’s commitment to expanding generic drug options against New World screwworm,” said Timothy Schell, Ph.D., director of the FDA's Center for Veterinary Medicine. “By authorizing both generic and pioneer products, the Agency is ensuring producers aren’t dependent on a single manufacturer or product to protect their herds.”
The FDA reviewed available scientific evidence and concluded that Bimectin may be effective in preventing New World screwworm infestations when used according to the authorization. The agency determined that the expected benefits outweigh the known potential risks.
Bimectin had previously been approved for treating and controlling several cattle parasites. The new authorization specifically covers its emergency use for New World screwworm prevention and does not apply to other forms of the product.
The injection is available over the counter, meaning producers can purchase it without a prescription. However, the FDA emphasized that cattle owners must carefully follow all product directions and safety requirements.
To help maintain food safety, producers must observe a 35-day slaughter withdrawal period after treatment. The product is not authorized for use in lactating dairy cows or in calves that will be processed for veal.
The authorization will remain in place until it is revoked or until federal officials determine that the public health emergency related to New World screwworm no longer requires emergency use measures.
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