When does a Puppy start mouthing?  Mouthing is when a dog routinely grabs people using their mouth without causing an injury.  That happens mainly during play, exercise, or whenever they are excited. For puppies under 5 months of age, it is still okay as a puppy explores things with its mouth. But if the dog … Continue reading The best way to stop your puppy mouthing. This can lead to a serious problem when not stopped at an early age from your dog.