WASHINGTON, D.C. – The U.S. Food and Drug Administration has 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 at the time of initial wound care. Ivermectin Liquid for Horses is not for use in species other than horses.
NWS is a flesh-eating parasite, which hasn’t had a confirmed domestic case since its eradication in 1966, has spent the last two years marching northward through Central America and Mexico. Its arrival in the American Southwest has mobilized a massive federal and state response. Newborn animals with healing umbilical wounds and animals with open wounds are particularly vulnerable to infestations, as NWS flies are attracted to these sites to lay their eggs. Left untreated, infestations can be severe and life-threatening.
Based on the totality of 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, and the known and potential benefits of the product outweigh its known and potential risks.
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.”
Ivermectin Liquid for Horses is a clear, ready-to-use solution and 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.
