Hun, I know this hurts, but you did make the right decision by ending Scooter's pain and don't fell bad for that.
As far as the other dog. I know that this is not exactly what you want to hear, but I would go after your brother and report him to the Humane Society because he is not a good owner and he doesn't deserve to own a dog. People like him should not be allowed to have a dog. Teaching a dog to kill is abuse!
I'm so very sorry for your loss and my heart and prayers go out to you.
RIP sweet Scooter.
