July 15, 2026—The U.S. Food and Drug Administration today issued an Emergency Use Authorization (EUA) for Ivermectin Liquid for Horses (ivermectin oral solution) for the short-term prevention of New World screwworm (NWS) infestations (myiasis) in horses. The product is authorized for use when administered within 24 hours of birth or during initial wound care. Ivermectin Liquid for Horses is not for use in species other than horses.
“We at USDA have been working with our federal partners to prepare for any potential infestation of animals that may occur as a result of New World screwworm. Today’s announcement is another step in the right direction,” said U.S. Department of Agriculture Secretary Brooke L. Rollins.
NWS is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals. Newborn animals with healing umbilical wounds and animals with open wounds are particularly vulnerable to infestations. This is because NWS flies are attracted to these sites to lay their eggs. Left untreated, infestations can be severe and life-threatening.
For short-term prevention, not treatment
Based on the scientific evidence available, the FDA has concluded it is reasonable to believe that Ivermectin Liquid for Horses may be effective in the short-term prevention of NWS myiasis in horses when used as authorized. It has also concluded that the known and potential benefits of the product outweigh its known and potential risks.
“This marks the FDA’s 11th Emergency Use Authorization deployed against New World screwworm,” said Acting FDA Commissioner Kyle A. Diamantas, J.D. “We will continue to use all available authorities, act with maximum speed and deliver tools to protect animals.”
This EUA authorizes Ivermectin Liquid for Horses only for short-term prevention of NWS myiasis, not treatment. If a wound is already infested, or if an infestation develops after administering Ivermectin Liquid for Horses, contact a veterinarian to discuss treatment options.
“This authorization provides a short-term prevention option for horses, but owners and veterinarians should be aware of the limitations,” said Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine. “This product’s window of prevention lasts no more than 24 hours. So it is important that the product be used alongside other preventive measures such as bandaging, repellents and other fly-control methods.”
Solution available by prescription
Ivermectin Liquid for Horses is a clear, ready-to-use solution. It can be administered as an oral drench or via a tube going from a horse’s nose to its stomach. This product is available only by prescription from a licensed veterinarian. Do not use this product in species other than horses.
Detailed product information about Ivermectin Liquid for Horses can be found in the Fact Sheet: Emergency Use Authorization of Ivermectin Liquid for Horses (ivermectin oral solution) for New World Screwworm (NWS). This EUA will be effective until it is revoked or the HHS Secretary terminates the declaration that the potential public health emergency presented by NWS justifies the emergency use authorization of animal drugs for NWS.
Ivermectin Liquid for Horses is sponsored by Alberta Vet Labs Ltd. based in Canada.
Related information
- Freedom of Information Summary: Ivermectin Liquid for Horses (EUA 006681)
- Letter of Authorization: Ivermectin Liquid for Horses (EUA 006681)
- Fact Sheet: Emergency Use Authorization of Ivermectin Liquid for Horses for New World Screwworm (NWS)
- Letter to Horse Owners and Veterinarians about FDA-Authorized Drugs to Prevent New World Screwworm in Horses
- Animal Drugs for New World Screwworm
- Emergency Use Authorization of Animal Drugs for NWS
- Screwworm.gov – Unified Government Response to Protect the United States
About the FDA
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, radiation-emitting electronic products and for regulating tobacco products.