I am sorry for your loss. I was in the same situation. I can not confirm my chick was injured by the neighbors dogs, but we did have to fill in a whole dug under our relativly secure run the other day. And I was there several subsequent times when they went straight for that hole.
My neighbors are easily in ear shot of my coop. I yelled cockadoodle-do and renacted Foghorn leghorn skits (all the voices) for an hour.
There were some squeeling tires comming out of thier house next few days. But the dogs never came back on my property.
I am not saying it would work for you, but it did for me, probably because the other neighbors were gossiping about how crazy I seemed, untill the rumor went back around again and although still crazy, it seemed like I had a plausible reason. No direct confrontation/negotiation, no trapping and pound, no formal citations with animal control, and no SSS. I am proud of myself, but I am more proud of my neighbors now.
Good luck in whatever you decide. Just make sure you are within the law and let some time pass to have a cool head. It will help your aim in which ever recourse you choose