What Causes Yellow Stool in Dogs?

By Cindi Pearce

Checking out your pup's poop is not a glamorous experience, but the color of your dog's stool can let you know whether she is healthy or fighting an infection of some kind. If you notice your dog's poop has become increasingly yellow, this may be a sign of infection, digestive irritation, parasite, or food sensitivity.

Woman holding a small dog

A Sign of Infection or Irritation

Yellow stool can indicate that there is an irritation in your dog's digestive system or an infection. The yellow colored stuff is mucus, which acts as a lubricant to help move the stool through the intestinal tract and out of the dog's body. Yellow mucus is not typical. The more irritated the dog's stomach and intestines, the greater amount of yellow mucus will be produced. A dog's system can also produce yellow mucus in the stool because of a food allergy or as an indicator that the dog has an intestinal blockage.

Parasitic Diarrhea: Giardiasis

When a dog has giardiasis, an intestinal infection caused by a parasitic protozoan, his stool may turn yellow. However, the stool of an infected dog is usually pale, greasy and terribly stinky. A dog becomes infected when he eats the cyst form of the parasite. The cyst then opens up in his intestine and releases trophozoite, which is an active form of the parasite. They attach to the wall of the intestine and then divide and are passed into the dog's feces. If you notice these changes to your dog's stool, call your vet.

Upset Stomach

Yellow stool can also mean that waste is traveling very quickly through the small intestine. When a dog has diarrhea and it's yellow, it can also mean that he is eating foods that he can't tolerate; so the dog's food should be changed. Yellow diarrhea can also be caused by medications to treat parvo virus as well as pancreatic enzyme replacement pills. If you notice your dog having diarrhea, make sure to provide her with a lot of water. Fluids are very important to prevent dehydration.

Young and Old

If your dog is a puppy and is eliminating yellow poop, you need to take it to the vet. If a puppy drinks too much milk, his stool can turn yellow. Puppies can easily be killed by an infection, so treatment must begin immediately. If your dog is elderly and has yellow mucus in his stool, this needs to be addressed. Old dogs have difficulty fighting off parasitic infections or other illnesses.

Additional Causes

Yellow stool can also be a sign that your dog is having issues with their internal organs. Problems with the pancreas, liver or gallbladder can turn your pup's poop yellow. While the occasional color change is okay, consistent yellow stool is reason enough to call your vet.