Diarrhea symptoms are pretty obvious — look for loose, watery, or liquid stool. Because diarrhea can easily lead to dehydration, be sure your dog has plenty of clean water available, then take your pooch to the vet if the diarrhea persists for more than a day, or immediately if there’s also fever , lethargy, vomiting, dark or bloody stools, or …
https://pets.webmd.com/dogs/6-most-common-dog-health-problems