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Q&A: What Can I Do About My Dog's Constant Diarrhea?

Dr. Mark is a veterinarian. He has been working with dogs for more than 40 years.


Is There Anything I Can Do for My Dog's Runny Stools?

"My Golden Retriever, Buddy, is 8 months old. He has very loose bowels (like pudding) all the time now, itches and bites his feet, and shakes his head a lot. He's been tested for giardia and other parasites, but the tests were negative.

We currently feed him adult food (Purina ProPlan Sensitive Stomach & Skin, Salmon & Rice Formula). His vet tech wants us to try new food that has proteins that we've never tried for him, like bison or venison. I also thought about trying grain-free food to see if he has a gluten allergy. So I bought some Taste of the Wild Grain-Free Roasted Bison & Venison kibble. We're trying to figure this out. I was wondering if you had another idea that we could try for food.

P.S. He had loose bowels as a young puppy too, but it's worse now. He eats everything he finds on the ground…flowers, sticks, rocks. I keep him away from those if I catch him. I would love to hear what your thoughts are. Thank you!" —Cheryl

Common Causes of Diarrhea in Dogs

There are many causes of runny stools, as you already know. Here are a few of the most common:

  • parasites
  • bacterial infection
  • food allergy
  • inflammatory bowel disease
  • irritable bowel syndrome

How to Treat Chronic Diarrhea in Dogs

There are several options when it comes to helping your dog, including some things you are already trying. These include:

  • novel protein diet change
  • hydrolyzed protein diet
  • increased fiber
  • prebiotics and probiotics
  • medication

Novel Protein Diet Change

Buddy looks healthy, so my first step would be to try him on the novel protein diet, which is what you are doing with the venison diet. He may have a food allergy, and the ear shaking and itching would support that possibility.

Dog food companies produce their venison diets in the same place they make their food with chicken and beef, so I would prefer you make up a novel protein diet at home to avoid any cross-contamination (the article linked above has more information on making your dog's food at home).

Hydrolyzed Protein Diet

Hydrolyzed protein diets are processed in a way that makes them less likely to provoke an immune reaction. This type of diet is typically prescribed by vets to treat food allergies and inflammatory bowel disease (IBD).

Increased Fiber

A novel diet can take a long time to show results. If it is not working, I would try a high fiber level and see how he does. One of the most successful fiber sources to help dogs with loose stools is pumpkin.

For a Golden, I would recommend three tablespoons of pumpkin with his regular food each day. (Do not buy the pumpkin pie mixture, as it has spices that will bother him. If you do not use fresh pumpkins, use plain canned pumpkin or powder.)

Prebiotics and Probiotics

My next step would be prebiotics and probiotics. Pumpkin may be all he needs, but you can also look into beet pulp, which can change the bacterial flora (microbiome) in your dog's gut and provide a better environment for the "good" bacteria. (1)

You can use a commercial product or fresh, unflavored yogurt as your probiotic. A study of dogs with loose stools in a shelter showed that dogs had problems twice as often when not on prebiotics and probiotics. (2) I am not positive if this will clear up your dog, but it is worth trying if the novel protein diet does not clear things up.


If that does not work, I would try metronidazole treatment, but you will need to discuss that with your regular vet. Some dogs may have a giardia infection even when the fecal exam is negative.

If he does not respond to the metronidazole, your regular veterinarian might want to try prednisone to rule out an inflamed bowel, but you will want to do bloodwork first. Hopefully, all of this will clear up before you even reach that stage!


(1) Grześkowiak Ł, Endo A, Beasley S, Salminen S. Microbiota and probiotics in canine and feline welfare. Anaerobe. 2015 Aug;34:14-23.

(2) Rose L, Rose J, Gosling S, Holmes M. Efficacy of a Probiotic-Prebiotic Supplement on Incidence of Diarrhea in a Dog Shelter: A Randomized, Double-Blind, Placebo-Controlled Trial. J Vet Intern Med. 2017 Mar;31(2):377-382.

This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2022 Mark dos Anjos DVM