Another question about my rescue dog coming into the picture. He's 2 years old, GSD/husky mix. We just lost the pack leader that kept the other two dogs in line (he was a 17 year old eskie). Our 2 year old female chi mix is keeping her distance, but my 10 month old shep/hound mix is scrapping with the rescue dog. They are both neutered and get along pretty well most of the time (it's only been a day). Today a friend of my daughter came into the house (8 years old) and the new dog was excitedly jumping around her and pulling at her sleeve. Our shep mix (Arizona) just went off on him....jumped on his back, growling and going insane. I immediately regretted letting my daughter's friend in and told her she had to go. Then this evening some sniffing again turned into a fight. The rescue dog is blind, easy going, and bigger than Arizona. Is this a fight for position? Does he see the rescue as weaker due to the handicap? Should I discipline Arizona when he starts a fight? Help!