Post pictures on facebook , if you don't have an account ( and I don't blame you if you don't ) get someone to post for you ,
More dogs are found these days on social media than any other way .
If you still don't hear anything then you've done your due diligence . Seeing as you have already contacted the local animal shelter .
I would be very very hesitant about posting pics of it. I've been in this very situation before. My wife posted pics and within a couple hours we had 4 different people claiming it as THEIR dog. It was easy to tell when we allowed each person to come identify the dog that it was not their dog as the dog wanted absolutely nothing to do with any of them. You can make a post though saying you've found a GSP and let them send you pics of their dog that they think it could be
