My fiance & I had taken in a rescue puppy, he is a 4 week old Pit Bull, Dai Ca, with that of course he doesn't have the proper learnings from his mother. My Pomeranian, Chanel, 9 months, isn't really well mannered when it comes to play, she can be a bit rough & because of this, Dai Ca has become a bit more rough. She doesn't really teach him "owe that hurts" she just gets rougher with him. They love each other, but I don't want him being this way when he gets older. What can we do to help with this?