Ecovet Fly Repellent provides a new, innovative solution for fly control. It contains no pyrethrins or essential oils but rather is a blend of natural fatty acids in a silicone oil base. The fatty acids act as a repellent by confusing insects' directional ability, making them unable to locate or land on your horse. The fly repellent will protect your horse from flies, gnats, mosquitoes, ticks, lice, and more, without causing harm to other organisms or the environment. It is a great option for horses with sensitive skin. This formula is made by a veterinary-owned company, and is tested and endorsed by experts.