I agree with the other PT members. He probably is adjusting. Rusty, our 11 yr old foster was the same way at first. He wouldn't eat or drink for a few days. I got him to eat raw ground beef and some raw chicken, but he only took a little bit of it. He did the whole stretching thing too. Now he is adjusted well. Give him some time and try some raw beef or chicken if you can. A vet visit does not sound like a bad idea. Good luck and please keep us posted.