Elmo has started to attack my two Chihuahuas, Sheltie, Collie, Schnauzer. He jumps on top of them and goes after their neck, I cannot put my 2 Chihuahuas down on the floor when he is out of his crate, same goes for my Sheltie and Schnauzer. Collie, Elmo goes up to her and growls and forces her to go outside in the cold. What do I do? I Love My Boy Elmo, but I love all of my other dogs too. He would kill the Chihuahuas if I put them down on the floor in from of him. I am a nervous wreck, I cry about this What Do I Do?? Isn't there a collar that I can put on Elmo to make him stop this aggressive behavior? Please Help Me I Love Elmo, I do not want to have to find him a new home, but I am terrified he will kill My other dogs.