Is your dog vicious? To be honest I won't work with vicious dogs. I can train dogs but I'm not on that level of training. I won't even try because if I do it wrong your dog could get worse. It's not worth the money to me. Contact a canine behaviorist. Those are the people you should talk to about that issue. Just know not all dogs that bite or growl at people are vicious. Sometimes it's a fear thing. They're not vicious they're just scared. It's a 'fight or flight situation' in they feel fight is their only way out of the situation they're in. Dogs should not be put down for being fearful. Never force a dog to "face their fear". That's like throwing you in a room full of something you're scared of and telling you to get over it. It's wrong and can do more harm than good. It's usually a slow process.

While training them I don't use treats. I use attention (pet them while saying good boy/girl excitedly). It gets the dog excited and wanting to learn more. You will be working with me. You know what makes your dog learn the fastest so it's really up to you on you're praise will be giving him/her.