Dogs bark for a variety of reasons. They could be alerting you of an intruder (alarm barking), demanding your attention (request barking), trying to drive off something or someone they are afraid of (fear barking), or they may simply be bored (boredom barking). In order to control excessive barking, you must first figure out what type of barking you are dealing with.

Request Barking
Many dogs learn that barking gets them what they want (food, attention, d door open, etc.). If this is the kind of barking your dog is exhibiting, you must teach him that the behavior no longer works. To do this ignore your dog completely when he barks at you. This is what we call putting the behavior into extinction. By removing the reinforcement (whatever it is he is used to getting when he barks) the behavior should disappear. Keep in mind, however, that because this behavior has worked for so long it may get worse before it disappears. It is very important that you DO NOT give in because this will only make the behavior stronger. Once he is quiet you can give him what he wants if it’s appropriate.

Fear barking
If your dog barks at something or someone out of fear you will have to work to change his emotions about the scary person or thing. This is called counter-conditioning. Get some really yummy treats (hot-dogs, chicken, cheese). Set up scenarios in which the scary person or thing arrives on the scene, but is far enough away that your dog is aware of it but does not react. Start giving him the treats when the scary thing comes into view and stop when it leaves. Slowly have the person or thing get closer and closer while you are giving your dog the treats. Over time your dog should change his opinion about the person or thing he was afraid of because it will now predict great treats.

Boredom Barking
If your dog barks when he is left alone he may just be bored. Increasing his physical and mental stimulation should help. Try the following suggestions:
1. Exercise him well before you leave. A walk is not always enough- play fetch or the recall game (having him run back and forth between two people) for 20 minutes. 
2. Hide food around the house for him to search for while you are gone. 
3. Leave him with a toy stuffed with food (Kong toys or hollow marrow bones work well). 
4. Practice simple obedience commands (sit, down, stay) every day. 
5. Teach him some tricks and have him perform them every day. 
6. Play hide and seek with his toys. 
7. Play hide and seek with family members. 
8. Leave a radio or TV on when you are gone. 

Separation Anxiety
If your dog barks only when you are not home it’s possible that he is suffering from separation anxiety. Dogs with separation anxiety often show other signs that indicate that they are anxious about being alone. If your dog is overly attached to you and follows you from room to room, or if he shakes, pants or cries as you prepare to leave for the day he may indeed be suffering from separation anxiety. You should consult a behaviorist to help overcome the problem.

Alarm Barking
If your dog barks at intruders, like the mailman, delivery people, or neighbors walking by his property, most likely his barking stems from territorial behavior. Alarm barking is a natural behavior in dogs and we can’t expect to completely eliminate it, but we can learn to control it. To deal with this type of barking you will need to teach your dog a ‘quiet’ command. Set up scenarios whereby someone walks past your house and triggers your dog to bark. After 3-4 barks, show your dog a really special treat (hot-dogs, chicken, or cheese). When he stops barking to retrieve the treat say “quiet” and give him the treat. Repeat this until you have paired the word “quiet” with his silence a dozen or so times. Then try to use your quiet command to stop his barking without showing him the treat. If he learned the command, he will stop barking, and you can go ahead and give him the treat as a reward.

If your dog continues to bark when you show him a treat or when you say “quiet”, you may need to use a benign aversive to interrupt the behavior. After the 3-4 barks, say “quiet” and then blow a whistle, shake a penny can (empty soda can with some pennies inside), or squirt him in the face with a watergun. The idea is to startle him into being quiet. Once he stops barking, say “good boy” and give him a treat. Repeat this until he will stop barking when you say “quiet”.

Dogs learn very quickly that their barking often makes the intruder go away. This is the case when your dog barks at the mailman. He thinks he is doing his job of protecting his home very well because when he barks the intruder leaves. If this is the case you must condition a new behavior when the mailman comes to the door. Set up scenarios whereby a friend “plays” the mailman and comes to your door and rattles the mailbox. Every time he comes to the door, have your dog sit quietly for a treat. A key component to this training is that the fake mailman should not leave until the dog is quiet. This way the barking is no longer “working” to drive off the intruder.