My friend has a neutured male pit bull and a few days ago she adopted a 7 month old neutured male mastiff. She said when her and her husband took him for a walk at the shelter there was a cement rabbit statue and he was freaked out about it(really scared). They went to the local pet store and he was growling and lunging at other dogs, but setteled down a bit after being there. Then when they got home they (in seperate cars) took the 2 dogs to the park to introduce them on nutural territory. Everthing was good not growling or lunging. They took them for a walk the two dogs walked nicley next to eachother. That nite at their house they kept both dogs on a leash but they seemed to get along. She said that today they played a bit then layed down and got along great, but then the Mastiff started a fight. It was broken up before any damage could be done, but she is having second thoughts on this now. They have already enrolled him in beginer obedience and start on Saturday.So I told her I would ask this question so that maybe Liz could give some input. Can this behavior be corrected or should she return him to the shelter?I should mention that her pit bull is in no way aggressive to other animals, he and my pit bull play together. And the MAstiff seems scared of almost everything he comes in contact with.