Q. My dog is pooping a lot of blood
DR. MASSIMO ORIOLES, DVM, MRCVS
A. That could be due to different reasons such haemorragic gastroenteritis, parasite infection, toxicity, coagulation problems, neoplastic disease and many others. Usually a large bowel problem would cause fresh blood in the feces, whereas blood coming from the first part of the gastrointestinal system would cause black/dark feces (the blood gets digested and assume this dark color).
I would strongly recommend to take her to your veterinarian for a check up, find out what is the underlying cause and have appropriate treatment.