My dog has had diarrhea fairly constantly since Sunday morning. She has never had any major illnesses before and we are concerned. She has been to the vet and had blood tests done and has also been put on a drip to try and flush out her system. She continues to have diarrhea. The vet says that her liver is not a concern and, after initial x-ray, there appears to be nothing sinister. My dog still has an appetite. She has been drinking a fair amount of water and her faeces are very loose. There was a small amount of blood in her faeces this morning. Do you have any thoughts on what this could be?