Health Topics  >  Digestive  >  Diarrhea

What is diarrhea in dogs?

Unformed or loose, soft watery stool – sometimes in larger amounts than usual, but more frequently – are all signs of a digestive problem. For most dogs, the normal frequency is 1-2 bowel movements a day, sometimes 2-3 times. Refer to the Bristol Stool Chart below to help determine what healthy dog stool looks like.

A dog with diarrhea is one of the most common signs of illness that dog owners experience, and also one of the top issues that vets see. Although quite common, diarrhea can actually be the result of serious life-threatening diseases such as cancer or organ system failure – or it can be a secondary issue due to a slight diet change. 

Diarrhea is often categorized as either large bowel (typically smaller volume, more urgent, mucusy and sometimes with frank red blood in it where the dog is seen straining), or small bowel (large volume, very liquid, sometimes black in color and very very smelly), it can also be both of these. Diarrhea can be either acute (sudden onset) or chronic (lasting for weeks or months). 


How to use the Bristol Stool Chart:

The Bristol Stool Chart or Bristol Stool Scale is a medical aid designed to classify stools (known as ‘feces’ or ‘poop’) into seven groups. You can use the Bristol Stool Chart to check what your dog’s stools are telling you.

Every dog will have different bowel habits, but the important thing is that your dog’s stools are soft and easy to pass – like types 3 and 4 below.

  • Type 1-2 indicate constipation
  • Type 3-4 are ideal stools as they are easier to pass, and
  • Type 5-7 may indicate diarrhea and urgency.