Our older dog (9) just had a bout with throwing up something that looked and smelled like poop, and it turns out he had an intestinal blockage. Our vet said that the vomit smells and looks like poop because, essentially, it IS poop--because there is a blockage, the dog can't process all of it out of the rectum, so some of it comes up through the mouth. Please mention this to the vet. Our boy didn't need surgery--medication helped clear the blockage. Good luck with your girl!!!
