Like human babies, puppies grow baby teeth when they are born, only that they have it earlier on as compared. The shift from baby teeth to adult teeth occurs in two months, between 4-6 months of age. When puppies are teething with their set of 28 razor-sharp teeth, it is pretty intense while also giving way to a set of 42 adult teeth. Puppies could teeth your hands, toes and whatever they find and could be a little annoying to you. This period could be uncomfortable and painful for your puppies as well.