Have you said anything to your neighbor?
My next door neighbors have 2 English Mastiffs, close to 400 pounds of dog flesh. The dogs were both in the house when burglars broke into the master bedroom and stole jewelry. They had to know the dogs were there and were not deterred
On more than one occasion. She apologizes for the noise, puts them in the house and they stop barking, and then she lets them out again 30 minutes later when the barking starts all over again.
I have never had a dog, big or small that barked constantly.
You obviously never had schnauzers. The neighbor has had as many as 4, but I suspect someone turned her in to the county (max three dogs without a kennel license) She usually has three, but sometimes only two. I keep a log so that if my wife agrees I'll turn her in to the county for harboring public nuisance animals. However, my wife doesn't want to "start trouble with the neighbor." I'd say that the neighbor has already sted trouble.