I went through this about 25 years ago. My escape artist Yellow Lab got out somehow, and just dissapeared! I put the word out around the neighborhod to all the kids that whoever finds him got 50 bucks. They looked frantically, but no Joe. After a couple of days, I began checking the pound every day (they had him before and denied having a yellow lab when I called them!) and not a sign of him. I was a mess, wondering what happened to him. There were two major roads and it was summer, and 110 degrees out in Las Vegas. My other dog whined 24/7 and wasn't eating much.
I put an ad in the paper, not hoping for much at all, but the first day it's in there, the ad above it says "Found- Large Yellow Lab, very friendly" It's two blocks away! I call them and ask them if he has a tattoo in his left ear, she looks and says "JR38". It was him! He had been at that house the whole time, and somehow all the kids and I missed him, even though I passed the house at least a dozen times during the week+ he was gone..
The kids at the house were planning on keeping him, and were very upset when I came to get him that afternoon. I offered them some money for the food he ate and for the cost of the ad, but they refused.
You never know, you may get lucky too...