Melissa Hinesville, GA 9/1/2010 6:51:04 AM I just adopted a Collie mix and he is a little over a year old. For the most part he is ok walking on a leash. But when we approach other dogs he gets really aggressive. Just the other day he was able twist himself off of his leash and he ran across the street and attacked the other dog. He didnt hurt the dog but he did scare him. What can I do to get this under control? Also, he is great with children and humans.