Dogs in my neighborhood roam free as well. Most people here don't have fenced yards, so the dogs run around as a big pack. We put up a fence and inside that built another one to keep our dogs separated from our chickens and away from the exterior fence so they won't dig under to join the pack. One of the neighbor dogs started climbing fences a couple months ago and killed one of my chickens. The neighbor saw it because he brought the chicken to her. I now keep my hens in a covered samll run instead of letting them free-range. The dog still comes and jumps all over the run, freaking my birds out. Neighbor told me to just scare him away, but he returns a few minutes later. I got my son a paintball gun for Christmas; curious to see how well it works. The dog is at a kennel now while the owners vacation, but I assume he'll be back next week. I will let the owner know what I'm up to.
Good luck!