My Yorkie is holding his butt up and front paws down, and also held up one of his back legs for a while.
Now he is gingerly walking, where he usually hops around. He isn't drinking and acts like his jaw is bothering him. Opening and shutting his mouth a lot.
Hi
I wish I could help with this, but your dog needs to see a veterinarian for sure. These symptoms are odd and I have no idea what could be causing them I'm afraid.
It's a situation where you need a professional to examine your dog and give you an accurate diagnosis. That way you can get him the treatment he needs. It's always best to get a diagnosis and treatment as quickly as possible as that way the recovery is also quicker (and usually less expensive!), so please have your dog see a vet asap.
Best of luck, hope he's doing much better soon.