I have always had a minimum of 4 dogs. Of late they have passed from old age except my Yorkichi. I adopted a 6 year old toy poodle for company for her, but she shows jealous aggression towards him. I hadn't noticed that she did this to our big dogs too, because they ignored her when she did this. She also barks almost hysterically when someone comes to the door. How do I stop this before she gets in a fight with my new dog?