Help!! I have just adopted a 4 year old border collie mix, I would not have if I knew how old she was BECAUSE she has been the only dog, has no training to speak of, etc. I have a shepsky I have raised from puppyhood and she will be two on mother's day. My question is this, she is a freaking resouce hog, she has never had to "share" anything or anyone before. She just quit snarling at the humans but is still mean to my original dog. what is the best I can do? Thank you all in advance.