You can give ivomec as young as a week old, but only a drop. I have given it as early as a week before, but my nerves got the best of me and there are easier wormers out there, I usually wait till pups are a month old before giving them ivomec. The proper dose is 1/10 cc per 10 lbs. With pups you dose accordingly. You can google drops from a dropper, to 1/10 of a cc conversion. Hope that helps.