If she is having an inner ear problem like some of the freepers have suggested, it also causes nausea. Try giving her a dramamine (from drug store) its safe for dogs and is she is having problems from an inner ear inflamation, that would also cause her to lose her appetite. A rescue I had developed and inner ear problem and they even have a hard time walking, will fall etc, balance is in the inner ear. My dog spent the night at the vets and had an IV I took her home the next day, she was also staggering before I got her to the vet.....its not serious, but needs attention..
I am taking him to the vet tomorrow. Thank you all for your suggestions and your kind support.