Having 4 cats, all that tend to have bouts with Gingivitis, I would guess that it might be the inflammed gums causing her to not want to eat. I get either Clindamycin or Anitrobe drops and give treatments every few months to try and decrease the problems of the Gingivitis.

Hope Peggy is feeling better soon and BTW I would most certainly not think that a catnip mouse had anything to do with her situation.