I am in the same situation as you, I have 5 Yorkies and two of the sisters are always going at it, sometimes it is terribly scary. They love eachother but then they fight so visciously. One of the girls even attacks her mother. I have two males, one is our baby and the other is one that I rescued from a puppy mill. He is timid and just coming out of his shell. Now the baby boy is attacking him. It is terrible. I am so sorry for you but you did the right thing. Warmest Regards, Lisa