I have a four year old neutered male dobe. We live in a two family house. A new family moved upstairs this weekend with a chihuahua. My dog socializes well at dog parks. When he is in the house, on the porch, or in the car he barks aggressively at other dogs. I want the dogs to get along and be comfortable with each other but I am afraid my dog will feel territorial initially and intimidate the other dog. My dog puts up a good front but when faced, with no barrier between himself and an adversary, he tends to cower or if it is a dog, he wants to play. I have never seen him with a dog a small as a chihuahua. At our previous residence we a german shepherd for a neighbor and they got along great! What is the best way to introduce them and avoid the territorial stuff?