Can you call the emergency clinic and describe what is going on- they will probably know from what you are describing if she can wait until 8 tomorrow. Our doxie Gretel (ATB) suffered from chronic colitis and sometimes had blood and mucus in her stool- we would have to restrict her diet and put her on Metronid(sp?) for a few days. But this may be something totally different so if it were me I would try to talk with the vet this evening and see what he thinks- good luck with this-