I have an 8 year old pittbull named Tiger Lilly. She can sometimes be dog aggressive when walking through a park on her leash. She has lived with other dogs in the past and had maybe one of two problems when left alone with other dogs. My son is asking for his first dog of his own and is at an age where he is capable of taking care of a puppy. My question is, is there a way to break her of her dog aggression? Or should we not even consider getting another dog? If we did decide to get another dog what is a good non territorial dog? Thanks for the help.