All I have to say is, Holy shit! What a pack of asshole some of you guys are!!! Honestly if a dog barking in the backgound bothers you so much that you want to poison it and shoot at it, maybe you have some mental issues you need to seek help for. There are a lot of other people and animals living in this world who do shit that makes noise. Just part of living in the city. Learn to live with it, or find a decent way to deal with it. Otherwise maybe you need to live in a little soundproofed room. Jesus, what if they had a baby that was crying? Or kids running aound the yard yelling. How about an airplane flying overhead? Those things sometimes even louder than dogs. Would you shoot at them and try to poison them too.? How about I just shoot at you with my BB gun every time you drive past me at the lake house with open exhaust or a loud stereo on your boat! Maybe invite you over for dinner and feed you a shitload of laxatives! That ought to teach you right? All I'm saying is there are a hell of a lot of better ways to train a dog not to bark that might not make your neighbor want to kill you too or get you arrested. Google it, or go buy yourselves a book on dog training or get one for your neighbor. If the dog only barks when your neighbor isn't home, he probably doesn't even realize it or thinks he solved the problem. I'm sure if you explain to him that you were considering shooting at the dog and trying to poison it, maybe he would take the matter more seriously, or at least realize he has complete assholes for neighbors and move somewhere else.
just remember no one likes your dog as much as you do
and all the noises you mentioned are short time
the dog that barks constantly need to be dealt with
the owners don't care because the dogs don't bark while they are home
If you think its OK for your dog to bark for hours while you are gone the you have a major mental problem