Puppies typically stop teething when they are about 6 to 7 months old. The teething process usually starts around 3 to 4 months of age, when they begin losing their baby teeth and their adult teeth start to come in. The adult incisors and canines erupt first, followed by premolars and finally the adult molars, which come in last between 5 to 7 months of age. By around 6 months old, most puppies have all 42 of their adult teeth. While the teething process generally lasts about 3 to 4 months, some puppies may continue chewing behaviors past this period out of habit or boredom. The exact timeline can vary by breed and size, with larger breeds sometimes teething sooner than smaller breeds. In summary, puppies usually stop teething by 6 to 7 months of age.