Optimum deworming program for control of Strongylus vulgaris infections is achieved by reducing the infectivity of the pastures. When horses are running on pasture in temperate North America, maximum pasture infectivity occurs in October - December. Safe-Guard Paste 10% is administered orally at a rate of 2.3 mg/lb for the control of large strongyles, small strongyles, and pinworms. Each mark on the plunger rod corresponds to a dose of 5 mg/kg (2.3 mg/lb) for 250 lbs. body weight. Safe for pregnant mares, stallions, and foals. | Merck Safe-Guard Equine Dewormer Paste | Size 92 gram