I adopted a 4 1/2 year old Shepard mix about 2 months ago. She was in a shelter as a puppy and then again as an adult. I adopted her from the rescue group that got her out of the shelter. She is sweet and loving and always happy. She jumps on new people she meets but is always happy to see them. A friend was getting rid of a dog so I had her bring the dog over to see if they would get along. 30 seconds into the meeting my dog attacked the other. It took 3 of us to get them apart. She ripped the dogs ear requiring stitches. It was horrific. I should add that she goes nuts when she sees other dogs when we go for a walk, I thought it was because she wanted to play. Clearly this is not the case. Now I don't know what to do. I am afraid to take her for a walk for fear of her getting loose. I don't know if I should be concerned about her around children, and I am devastated that my sweet girl could turn into this animal I did not even recognize. I would appreciate any advice.