Pfizer Solitude IGR by Zoetis, formerly Pfizer For feed-through fly prevention and control of house and stable flies in and around horses, horse barns, stables, paddocks and race tracks. When mixed 1/2 oz. into a horse"s ration daily according to the directions, will prevent house and stable fly development. Solitude IGR (cyromazine) is a non-organophosphate that has been safely used in horses since 2001 and undergone extensive research to prove its effectiveness and safety. Features: Repeated