[uberglamorous]

As a breed, there have been many well-documented cases of aggression in Chihuahuas. There are just some of their kind that displays a natural aggression towards strangers. Some of them are inherently possessive of their food, toys, or owners. In general, any breed of dog who acts this way needs basic obedience training and socialization.

These are the two key steps in reducing any dog's aggressive tendencies. On a broad scale, he'll need to get into the habit of following basic commands from you. Assert yourself as the alpha dog so that he'll learn to stop unwanted behaviors after you scold him.

If possible, take him out for a daily walk to give him a chance to get acquainted with other dogs and people in your community. This is especially important in reducing his fear of strangers. You can actually find more information in the Secrets to Dog Training book (formerly Sit Stay Fetch). This book really helps me whenever I have to deal with any problem concerning dog care.