My dog once got into some chocolate, was very ill, with
bloody diarrhea. I was quite scared to see the blood there, but I took her to the vet,
and he said that blood in the stool was very common after eating chocolate, or anything irritant or toxic like that. My dog was OK, but she had to be fasted a day, and then only given small amounts of very bland food such as boiled fish and rice, or chicken and rice.
Can you be certain your dog hasn't eaten something possibly toxic like chocolate?..