Flies adapt. Farnam answers. Farnam fly spray Endure Gold is the next generation of equine fly spray, engineered for fast, lasting fly control that stands up to tough conditions. This advanced horse fly spray combines six active ingredients, including Acetamiprid and Farnam-exclusive, EPA-approved Etofenprox, to deliver powerful insect control with rapid knockdown of horn and face flies in just 15 minutes and continued protection for up to 14 days when used as directed. As a premium fly spray and fly repellent, Endure Gold kills and repels stable flies, horse flies, face flies, house flies, horn flies, black flies, biting midges, gnats, mosquitoes, and ticks, including deer ticks that may transmit Lyme disease, making it a dependable horse tick repellent and mosquito spray for horses. This horse fly repellent is field tested by equestrians under real working conditions and formulated to maintain performance through heat, sweat, and turnout to protect from sunup to sundown.. Designed as a non-oily equine insect repellent, Endure Gold works as a reliable fly repellent outdoor solution and pairs well with SuperMask II and SimpliFly Feed-Thru Fly Control for a full-season defense from stall to pasture. When ordinary sprays fall short, Endure Gold delivers the long-lasting horse fly deterrent performance that horse owners trust.1 Gallon