First, let me state that I am a dog lover. Have always loved sloppy dog kisses. BUT, any dog who comes on my property without invite, (where I free range my poultry) is a predator. If the owner is within sight, I would give them a verbal warning. If no owner present, I would, and have in the past, catch the dog, tie it up, and wait a reasonable time... perhaps an hour or two, then call ACO to pick up the dog. I once had a neighbor's dog enter my run and kill half of my flock. I caught the dog, while it was still covered with blood, tied it up, and called the owner. Her response: "Not my dog. My dog is right here and has been here all morning." So, my next step was to call ACO. But, before I could get back in the house to look up the number, I hear the owner (from 1/4 mile away) calling her dog! Of course her dog did not come home! So, about 15 minutes later she showed up, I made her view the carnage, and told her I expected full restitution before allowing her to take her dog. She did reimburse me for the dead chickens, but no amount of cash can cover the terror to the birds, and the amount of loving time spent raising those birds to POL, or even compensate for the lost production. So, predators, with or without a collar get invited to target practice, hauled away in the paddy wagon, or owner gets one chance to grow up and accept responsibility.
Second, a secure run is excellent insurance: I have electronet run, with coop enclosed in the run. When I build my new coop, I plan to enclose the perimeter with a triple strand of hot wire. But, I still exercise the right to free range my flock on my property.