First thing Monday morning, we took her to the dog vet. After a thorough check up, including a liver panel to make sure that the Rimadyl she's on long term did not cause any damage, Linguini was pronounced quite healthy (considering her advanced dog arthritis). She was prescribed stronger pain meds to be taken sparingly ONLY as needed. She was also prescribed an anti-inflamatory drug to keep her from having dog diarrhea. She was already on DES for her incontinence, but her dosage was increased.
We're still waiting for the culture, but for now the dog vet was pretty clear:
The Happy End