Beginning with the first puppy worm treatment at the age of two or three weeks, pet parents should deworm the puppy again every alternate week until the puppy is 12 weeks old (4th, 6th, 8th, 10th, and 12th week). After this, you should deworm the puppy once every month until it is six months old. After that, the puppy can be shifted to a deworming schedule for adult dogs.