Dogs and cats will think nothing of crossing from one city to another. Most dogs can run at a steady pace of about 10-15 miles per hour, so it won't take long for a dog to go a long way. Keep checking each animal shelter every other day. Don't give up easily. Don't forget the children.
Children are out in the neighborhood more than adults, so they can be very helpful.
If you offer a reward, do not advertise the amount. Remember that the ad will not appear until the next day. Some other people to notify include your mail carrier, neighborhood watch captain, school crossing guard, neighborhood police officer, and paper carrier. If you have a purebred pet and no photo, look at the library for a picture of a similar pet. Place posters in neighborhood gathering places such as grocery stores, laundromats, veterinary offices, libraries and schools.