Bailey is a 4 year old pitt bull mix that we adopted from the SPCA when she was just a puppy. Someone had found her in a bag at the dump. She has been raised in a very loving environment and we have never had a problem with her except for her being so possessive about us. She can't stand for anyone to come close to the house. As for excercising she has had 2 ACL's on her hind legs and has bad arthritis in her hips so we try to keep it basically to walking on a lead because she goes crazy if she sees a deer in the woods or someone in the street. She is smart and follows most commands easily except for when she sees something close to the house and then she doesn't hear us at all. I will probably get her into obediance classes and if that works I will follow up with the underground fence. I don't want to take a chance of her getting out and biting someone or getting into a fight with another animal. Bailey was my first dog and has been a HANDFUL !! Thanks for the advice..it is very appreciated.