i have supplemented with selenium to the mares before the foals are born, and supplemented babies with selenium too, but don't know as that has as much effect after they are born.once they are born crooked I am not sure how long before their joints and bones are set enough they can't be changed much. My farrier says that corrective trimming is usually most effective before 4 months whil most measures taken after that time are mostly cosmetic and don't do much to change actual conformation. I suspect that time frame may be the same for attempting to change conformation defects through feeding supplements. we are very low in selenium in Illinois pastures and water...
never used the shots, know nothing about that....