Grrrrr....that happens to me ALL too often. One day is this black border collie, running around time (I believe she's always free) and another dog who comes and roams around town when "he doesn't get fed" and even today, I was walking Major and I noticed he was pulling a bit harder than usual but my head was down because of the cold wind. Well we were almost at my house, I look up, and this black and white border collie is walking out of my yard. I turned Major around and started walking the other way until he left, which thankfully wasn't too long.

I'm sorry I don't have any advice, but I can't stand people who let their dogs loose!