Answer

Hi again, Jackie, and thanks very much for your reply with additional and helpful information.

You are absolutely RIGHT! You ARE rewarding his barking by 'responding' with attention, and toys and treats. You're trying to distract him, and instead, he interprets your actions as 'positive reinforcement' of his barking. So, this is what you'll have to do to modify his behavior (and this is a 'process', so you'll need to exercise patience, but it WILL help): (from http://www.sniksnak.com/doghealth/barking.html)

"My dog constantly barks. What does he want?

Attention getting barking can be problematic and is often reinforced by owners giving in to their dog’s demands. Allowing a barking dog indoors, or feeding, patting, praising, playing with, giving a toy, or even just going to a barking dog to try and quiet it down, are just a few examples of how a guardian may unknowingly reinforce barking. Never reward barking with any type of attention, even occasionally.

How can I train my dog to be quiet?

Training the dog to a "quiet" command is an invaluable aid for controlling undesirable barking. You must find an effective means of quieting the dog, which should be preceded with a command such as "Quiet." Just loudly telling your pet to "Be quiet," will not be understood.

One of the most practical techniques for teaching a dog to cease barking on command, is to first, be able to command the dog to begin barking on cue. Use a stimulus that will cause the dog to bark and pair it with a "bark" command. Numerous repetitions allow the dog to associate the word "bark" or "speak" with the action. Dogs that bark on command can then be taught to turn off the barking by removing the cue or stimulus, and giving a "hush&quote; or "quiet" command just before the barking subsides. As soon as your dog is quiet, give a favored treat or reward.

It can be difficult or impractical to teach a dog to be "quiet" on command if the barking cannot be predicted or "turned on" or if it is too intense.

Another method to teach a quiet command is to wait until your dog is barking, say to a doorbell and while he is barking place a very tasty food treat by his nose. Most dogs will stop barking to sniff the treat. At the same time you must say the word you will use for quiet, such as "Silent", "Hush", etc. When the dog is quiet (as they will be because dogs cannot sniff and bark at the same time) you can praise him, say "Good, quiet" and give the treat. Again, as with all new tasks, numerous repetitions are necessary for lasting learning.

Alternately, distraction or remote punishment devices (see below) can be used to disrupt the barking. One of the most effective means of interrupting barking and ensuring quiet is a remote leash and head halter. A pull on the leash disrupts the dog and closes the mouth. Quiet behavior can then be reinforced first by releasing and then giving a reinforcer such as praise or food if the dog remains quiet." You can read the rest of these instructions at the link above. This will also help: http://www.sniksnak.com/doghealth/barkcontrol.html

I hope things improve, soon.

Cher