I had the same problem, only the neighbors dog would also try to attack my wife and I. The wife came home from work and the dog came at her so she ran in the house. She called me all hysterical she said the dog was in the coop. I was racking my brain as to how it got in. It literally chewed through the poultry mesh.
So I had already told the neighbors about their dog. They didn't care(crack heads)! So I called sheriffs department, told them it had attempted to attack us and had already killed one hen. They told me I had a right to protect myself and my livestock.
With that in mind....I told my wife to shoot the darn thing. When I got home from work, I had to drag a 75lb pitbull carcass across 5 acres to knock on the neighbors door and said here is your dog. Deputy came out after they called and looked at the evidence....pool of blood in coop, and one dead rooster. He told them they were out of luck. Have not had a dog problem since....they are all fenced in their own yard now.LOL
To protect myself we are not cruel to animals, as all of our animals except the chickens are rescues. 4 cats and 1 dog. We are avid hunters as well, so the wife did not let the dog suffer. It was a clean head shot.