Please note I'm not anti-dog but the stress of living next door to dogs that bark when they are home alone is awful. My neighbors have 4 or 5 dogs. If they are home we don't hear them much although they bark at us when we are in the garden. A few hours after they go out the barking will begin. We are detached but we can hear it all over the house and there's no escape.
I tried to ignore it for ages. We knocked on the door and told them. I've texted them as well. I feel guilty for messaging them to tell them that it's becoming a nuisance but my child has special needs. It probably happens every week although it could be more often as we of course don't hear it if we are not there. I've actually started spending more time out of the house which leads to spending money and avoiding using some rooms where the barking is more obvious (I know I sound like a nut case but unless you've been there you don't know what it's like)
The barking lasts for hours until someone gets home and has been up to midnight before. The other houses nearby don't really hear it because the sound comes through the side door of the house. I haven't made a noise complaint and would feel terrible if I had to but I have started recording the barking.
We had a massive row about moving house. We've lived here for decades. The house is perfect for us apart from this but sometimes the stress is terrible. They started off with two barking dogs and we spoke to them about the noise when they had two. IN the last few years they've added at least two more dogs that are in the house or garden all of the time.