For maximum control of parasitism, it is recommended that foals (2-8 months of age) be dosed every 4 weeks. To minimize the potential source of infection that the mare may pose the foal, the mare should be treated 1 month prior to the anticipated foaling date followed by retreatment 10 days to 2 weeks after birth of foal.Horses and ponies over 8 months of age should be dosed every 6 weeks.