I had the same problem with my dachshund over a year ago. I had moved from an apartment with roommates, to my own home. The shock of the move, combined with the pack (my roommates) being gone, caused my little guy to bark non-stop when I would leave.
I hired a trainer, and we fixed the problem super quick. It took only a few hours one night to remedy the barking issue. Here's a great point that my trainer said that really stuck with me. He said, "Your dog's barking is because he doesn't want to do what you want him to do. It's not because he's scared or lonely, necessarily. He wants to be in charge. We need to adjust his attitude."
So to fix this, we put my dog in the bathroom by himself with the door closed. I made it really comfy for him - toys, bed, lights on, etc. I also had him wearing a training collar with a remote control, that I had with me. I sat in the other room watching tv, and anytime he protested with whining or barking, I would hit the button on the remote. (just a non-harmful vibrate to his collar. Basically the vibrate is annoying to him.)
After a few hours of doing this, he just sat there quietly. When I let him out, I praised him a lot to reward him for his great behavior. I'm not sure how to do the same training without the collar. Maybe open the door and tell him, "NO!" every time he barked? That may take longer than if you have the collar.
If you are interested in getting one, I bought mine from Dogtra.com
. It's under products/remote training, and called "300M."
After that, I did not have any more issues with barking. I was so relieved, as I think my landlord (who was my neighbor) was on the verge of getting rid of me. We have lived there for almost 2 years now without any other issues with barking.
If anyone is interested in the trainer I used, he is located in California. His website is Aggressive Dogs, Dog Training Orange County, Temecula, Santa Monica Aggressive Dogs, Dog Training Orange County, Temecula, Santa Monica Aggressive Dogs, Dog Training Orange County, Temecula, Santa Monica
. If you do use him, please say you were referred by me (Joy with black doxie). Thanks!
I hope this has been helpful...Best of luck!