Hi. I had an 18 mo. old male GSD that attacked my 3 year old yesterday. Did sever damage to his ear and face. He was unprovoked and this is the 3rd time he showed aggression towards my 3 year old. He did not show any aggression towards my 5 year old or myself or husband. I am unsure as to what would cause him to do this. He was very well tempered until we were not around (in a different room) and then he just seemed to have it out for my 3 year old. The first 2 times he showed aggression towards our son we just thought he was playing rough. This time he actually attacked him and literally caused so much damage that he needed to have his ear surgically reattached. We are ask unsure as to what to do with the dog. I signed a release to allow him to be given back to the previous owner (at this point he is still up at animal control). The previous owner is a cop and said that he would do whatever we decided was best (put him down or not). The dog has been around other kids and was raised around this man's grandchildren. Our 3 year old son was not provoking him and was playing in the yard with our 5 year old son. He has never been anything but loving to the dog. So does anyone have any suggestions as to what would of caused him to do this?