Tabard is indicated for the control (repellent) of horse files, stable flies and mosquitoes on horses.
The active ingredient, DEET* interferes with receptors in biting insects that detect lactic acid and carbon dioxide, the primary attactants emitted by humans and animals
Insects exposed to DEET* are therefore unable to effectively locate a host.
DEET was originally developed by the US Army for protection of military personnel and was later registered for public use.