If there is more mucus than normal or if it seems that there is only
mucus with no normal stool present, your
puppy may have colitis. There are many causes of colitis. The most common is eating things that she shouldn't. This doesn't necessarily mean things that she has stolen without your knowledge, this can also mean foods that you are feeding her but are unaware that they can cause her harm. Rich foods, fatty foods and dairy products are common causes of colitis.