A dog that has red and formed stool may be caused by improper diet, parasites or gastroenteritis. It is best to go to the hospital for examination to avoid delaying the condition. When feeding your dog, do not feed raw or cold food to avoid increasing gastrointestinal burden, and do not feed hard and difficult-to-digest food. You can feed your dog an appropriate amount of probiotics to help regulate the intestines, and perform regular deworming in the body.