barking and aggression

Question
My 2 year old chihuahua barks at EVERYTHING. Every single noise he hears outdoors, he runs to the door and barks and barks. This happens all hours of the night and early morning, which interrupts everyone in the house's sleep cycles. We tell him "no" when he barks, but it does not stop him. He also barks at everyone he sees other than his owners. I had a friend over and he barked at him for about 2 hours and my friend eventually had to leave. I dont know why he feels so threatened. My question is, how do i get him to not bark at everything?

Answer
The dog doesn't feel threatened it is simply doing what it knows works to get rid of unfamiliar guests in its environment.  This is a very common problem with small breed dogs.  Owners seldom take the physical steps necessary with smaller dog to establish leadership and earn the trust and honor of the dog.  AS long as you continue to allow the dog to bark at these things it will only get worse.  This is a perfect opportunity for you to learn and understand the ONE, TWO, GOOD DOG! protocol.  Get control of the dog by putting a lead on it.  Preferably this will be a slip noose type lead like the "Whisper String".  Now create a situation where the dog will demonstrate the barking.  When it barks stop it by using a loud firm short "a"  AAAAAAAH sound.  Immediately when it stops barking praise it with strong verbal praise and physical pats on the chest and side.  If necessary you can give a tug on the lead to assist in getting you point across.  You may also if necessary simply grasp the dogs mouth shut to stop the bark.  Repeat the process.
This entire process should take only a couple seconds with the praise continuing for another 3 or 4 seconds.  You should look to get 15 or more reps in 3 to 5 minutes.  When you no longer are able to illicit the bark from the dog then praise it for not barking the same as when it quit barking.  Get at least 15 reps.  From what you say it should be easy to find things that make the dog bark.  I have worked with dozens of dogs exactly like this using this method with 100% success.  It is important that you are consistent in your application and keep the process short and precise.  The praise needs to follow the action of stopping the bark within 1/2 of 1 second or almost simultaneously.  
Here how it fits the ONE, TWO, GOOD DOG! protocol.   Your action to stop the bark, the "AAAAH", or lead tug or shutting the dogs mouth (ONE)  The dog stopping or not barking (TWO) Praise (GOOD DOG!)  Thus we have the ONE, TWO, GOOD DOG! occurring in a couple second with the praise continuing for a few more.  Learning this protocol will prove priceless in working with your dog and developing a better line of communication with it.  You can purchase my "ONE, TWO, GOOD DOG!" Booklet here: http://invincibleservices.com/html/one__two_good_dog_.html
Further question or concern please call DR. Hogan 509-991-0385  until 10pm Pacific time