I am beside myself! My one Westie, Violet, has attacked my other Westie, Lily twice in the past couple weeks. She gets Lily by the back of her neck and growls viciously. I have to pull Violet off her. The first time was over a toy. Today my neighbor came over when I wasn't home to deliver a birthday cake and card for me and after she got into the house, Violet attacked. My neighbor has come over before when I was not home and this didn't happen. Violet seems aggitated lately. I did call my vet and they want me to see their vet who specializes in behavior issues. Any thoughts? Has anyone experienced this? Violet is a puppy mill rescue and I have had her almost 4 years. Lily is older and my first.