It is as I thought; Shnoz has a stomach infection. After another particularly unpleasant morning walk we bit the bullet and took her straight in to see the vet. She is on antibiotics and anti diarrhea meds and actually seems to be brighter already, after just one day :) I truly hope it will just clear up after the antibiotic course. The vet thought it could be caused by pretty much anything. My guess is the raw crab claw she ate before I could wrestle it off her!!