We had people that lived in the house behind us that had 2 yippy dogs. All night, yip yip yip... Those dogs were outside pretty much 24/7 and I am not sure if they wanted food, water, or what.. After 2 years, they moved...
Now our neighbors right next to us let their 2 big dogs outside around 5:45AM and they both BARK (not yip) non-stop for 10 minutes. Annoying as heck! It wouldn't bother me as much if it was 8AM or something when I am up and gone to work, but 5:45AM when they are a retired couple that don't need to be up so early. I have yet to find a solution.
I did hear of someone putting an "anonymous" letter in someone's mailbox with a complaint letter that was nice, but firm, about the problem and stating that if things didn't improve that the police would be called for disturbing the peace or something like that. It was written as though it was from more than one person, although it never said it directly. Wording like "the noise can be heard throughout the neighborhood and is disturbing many families and households." This guy didn't ask anyone else if they were bothered, but made the assumption that they were so worded it so that the recipient would make the assumption that it WAS from multiple people. It had more pull that way.
That is a little more "passive" than a compact pistol or bowl of antifreeze, but should help out. Even if it doesn't fix the problem, you can use the fact that you gave him a letter as the basis for starting the noise complaint route.
