Sending prayers to keep Trevor safe and be found soon. Put an ad in the local paper in the lost section. Go back to the area at night with your other dog, and try calling for him then. Often they will hide when it's busy and come out at night. Go leave a piece of worn clothing near your office door to encourage him to go back there. Drive the route from there to your home, and paper the route with flyers. Often dogs will travel for miles to get home.