[Maximo]

Welcome to YorkieTalk. Sounds like you have a lot going on at home and the problems are escalating. If you have the means, I would recommend hiring a personal trainer, one that uses positive reinforcement methods.

At 8 months old, the dog is still a pup and still developing and is full of pent up energy. Is he neutered? Does he get daily exercise?

Do you leave your 3 year old alone with the dog?

It's difficult to determine the problem and solution without seeing behaviors first hand. Yorkies can be feisty and sometimes their play can be misinterpreted as aggression. Then you have a 3 year old correcting the dog in a way that may be heightening the dog's excitement, causing the dog to jump around and give a bite on the nose.

I don't mean to make light of the bite on the nose, but I will say that my older boy, Max, gives gentle "love bites" on the nose. It could be that your dog has not learned bite inhibition, how to control the bite. Once again, I'm not saying nose biting has to be an acceptable behavior in your home, especially with a 3 year old boy.

Many Yorkies enjoy "play wrestling," something they start as pups with their littermates. Your Yorkie may be treating your son as a littermate. Then you have to consider how your son behaves around the dog. How does your son play? Your Yorkie could be responding to the way your son pets or plays with him.

I personally don't subscribe to dominating a dog, and I prefer the positive reinforcement approach. A calm, confident, cheerful leader gets better results. The dog is more open to training. Tension only heightens the dog's anxiety and makes him more excitable, and more likely to display undesirable behaviors. An anxious dog is completely closed off to learning.

Before allowing your father to insist on putting the dog down, please ask here for references to Yorkies rescues. Their are many people here willing to help.