I had a puppy a few years ago that got stolen. Twice actually, we got him back the first time but the police said they couldn't do anything because there was no poroof he'd been stolen in the first place. Even when he was really stolen the second time there was not much we could do. Weirdly enough, a few weeks back this dog followed my mum and brother back while they were out shopping. It was my dog, but massive :| I mean he was a bunch of breeds and he looked unique, so I'm 100% it was him. Besides, why would a random dog follow them back? He had an address on him so we got the dog warden to take him there, but we gave him our number so the owners could call us. We wouldn't want him back obvs, we had another dog, but it was nice to know he was okay.
No call unfortunately, and can't remember the address. Oh well. I hope you're lucky enough to find your pet.