Sick Dog and Vet can't find the issue

[ChickieShelly]

Yes, that leads me to believe pano, it can come and go like some one else mentioned above. Your regular DVM that took the x-rays should have picked it up though, it is visible on a regular x-ray if the veterinarian knows what they're looking for (which they should, its pretty common in growing active puppies). I would keep giving her the Rimadyl as directed by your vet, and cage rest/leash walks for a few weeks. I know that is extremely hard with a puppy, especially a puppy that feels better, but it's much better for her in the long run!

I did a little breed research last night, since this is not a breed I commonly see. One of the biggest things I could find was Dental issues (missing pre-molars, etc). You did mentioned food adversion and crying out when taking a treat, she's at the right age for teething, you may want to keep an eye on her mouth in case of an impacted tooth growing or trying to grow in.

I attached a screenshot of Pano on an X-ray, for educational purposes, if you get a chance to look at the x-rays of your puppy again.