The U.S. Food and Drug Administration has issued emergency use authorizations for four animal drugs aimed at preventing and treating New World screwworm, a parasitic threat that can cause severe and often fatal tissue damage in livestock and other animals.
The authorizations include three products from Boehringer Ingelheim Animal Health USA: Ivomec (ivermectin), NexGard (afoxolaner), and NexGard Combo, along with an antiseptic wound spray with insecticide from Health and Hygiene Ltd.
These products are authorized for use across a wide range of species. In addition to cattle, treatments may be used in dogs and cats, as well as horses, sheep, goats, deer, birds, and even certain exotic and zoo animals, depending on the product.
The move follows a 2025 determination by the U.S. Department of Health and Human Services that New World screwworm presents “a significant potential for a public health emergency” with implications for national security and animal health.
Under federal law, the FDA can authorize the emergency use of animal drugs when no adequate, approved alternatives are available and the potential benefits outweigh the risks.