I have a 2 year old German Shepherd Dog who's been trained by a local dog trainer, she is an awesome pet. However,I had a problem at a local dog park that while she was doing her business I went running for a bag to clean up after her and a Rottweiller mixed dog came after me barking and growling. I stopped immediately and while the dog was growling at me she came from the side and attacked him and ever since that day she's no longer friendly with other dogs. As soon as a dog gets near she gets into a defensive stand, she obeys me as far as not to move, sit or down but no longer plays with other dogs, or can another dog get close to her. Is there a way for me to correct this problem without taking the risk of her to fight another dog? Sincerely, Jose Jones Sent from my iPad