Dog's diarrhea

CLOSTRIDIUM DIFFICILE: another reason of diarrhea in dogs

Another bacterium of the Clostridium family which lives with us is Clostridium difficile. So far there have been three main toxins secreted by C.difficile (A, B and CDT ) isolated and scholars try to check, which one is the worst. I am afraid these are purely academic discussions because at the present moment we don’t have any reliable cure to treat infections caused by C.difficile, not to mention their multi – drug-resistant strains.

C.difficile is considered to be the most common cause of human nosocomial infections (about 25%) causing diarrhea and sometimes leading to more serious complications like ascites, pleural effusion, acute heart failure, liver abscess, renal failure or pseudomembranous colitis.

Some recent researches suggest that in the anaerobic environment of the human colon, derivatives of certain organic compounds are present, helping Clostridium bacteria to reproduce. In a healthily balanced gut microbiota, these derivatives are removed by “good” bacteria, thereby reducing the reproductive chances of Clostridium.

If we treat ourselves with an antibiotic, it can act like a double-edged – sword, allowing the most virulent strains of bacteria to survive, while a lot of good microbiota is lost. Clostridium difficile or other pathogens will thrive in such “empty” intestines. The frequency of infections and mortality connected with it tend to increase with each year. Advanced age, weakened immune system, the presence of other diseases and most often – hospitalization, are high-risk factors.

Since a few years, scientists have been warning about new strains of C.difficile capable of producing 16 to 30 times more toxins A and B. Besides, the strains have multiplied their reproduction power. All of that ensures dominance in the environment making C.difficile a super-bacterium.

As for dogs, C.difficile are their commensal bacteria meaning they are not harmful as long as the mysterious balance of gut microbiota is maintained. C.difficile bacteria were found in stool samples from both sick and healthy dogs so in case of disease fecal examination won’t be helpful. Instead of bacteria alone, we should rather look for its toxins. It is supposed that A and B toxins are involved in diarrhea in dogs.

In many studies, direct application of any isolated Clostridium difficile toxin to an animal always resulted in symptoms of severe gastrointestinal dysfunction, so it can work the same way in dogs too.

It can but doesn’t have to – data from various studies is confusing and it’s difficult to draw unambiguous conclusions. The fact that different scientists use different medical tests to search for C.difficile toxins, means that they can obtain different results. None of these tests are perfect, even the most modern one like PRC (Polymerase Chain Reaction), or Elisa immunoenzymatic tests – in addition, they are calibrated for human not dogs readings. As far as I know, there is no commercially available test for C. difficile, approved (validated) for canine use.

People can suffer from C.difficile induced diarrhea also as a result of previous antibiotic therapy. It is unknown if the same thing happens to dogs but it is worth consideration. Another risk factor can be usage of drugs meant for decreasing stomach acidity eg. proton-pump inhibitors (PPIs), very often overused or misused in dogs. Stomach acid is one of the first line of defense against pathogens, Clostridium including. Use this drug carefully.

Finally, you should also avoid veterinary hospitals – 🙂 due to the increased exposure to this very bacteria in such places (in a similar way, people get infected during their stay in hospitals).

What to do then? Even the 21st-century scientific medicine seems helpless – IDSA and SHEA two powerful, opinion-forming U.S organizations, dealing with human infectious diseases and epidemiology, in the recommendations issued for the year 2017, for recurrent C.difficile infections, advice fecal microbiota transplantation instead of antibiotics. Such transplantation is supposed to revitalize the intestinal flora and stop infection. That treatment works for dogs too.

Meanwhile, new alternative treatments are being sought. Perhaps instead of killing the bacteria, we could bind its toxins directly in the intestines, using some clays? Some in vitro tests look inviting but still, it’s a long way to obtain the same results in vivo especially in the acute stage of the disease.

It seems that keeping the gut microbiota in balance is a crucial thing for us and our dogs. Healthy unprocessed food is a vital component of that balance (cook for your dog if you can o read pet food labels carefully if you can’t).

In case of gastric problems try to help your dog’s digestive tract and ‘good “bacteria with herbal teas : chamomile (Matricaria chamomilla), mint (Mentha piperita), fennel (Foeniculum vulgare) ,dandelion root (Taraxacum officinale), common nettle leaf (Urtica dioica), lemon balm (Melissa officinalis) or agrimony ( Agrimonia eupatoria) to name just a few.

ATTENTION: any herbal tea should be used in small quantities mainly as a kind of tonic supporting the body’s work. Do not try to heal your dog with strong infusions given in large volumes! Depending on the size of the dog start giving teas even with drops: 2-3 times daily, for a few days, then take a short break. Each herbal tea should be introduced separately! It will allow you to observe the possible side effects, including a delayed allergic reaction.




1 Stefano Di Bella, Paolo Ascenzi, Steven Siarakas, Nicola Petrosillo, and Alessandra di Masi.

Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects

Toxins (Basel). 2016 May; 8(5): 134.

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2 Stanley L. Marks, BVSc., PhD. Dipl. ACVIM (Internal Medicine, Oncology), Dipl. ACVN .Associate Professor

Bacterial-associated Diarrhea in the Dog – A Critical Appraisal . Department of Medicine and Epidemiology,University of California, Davis,School of Veterinary Medicine,Davis, CA 95616

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3 Nadira Chouicha, Stanley L. Marks. Evaluation of five enzyme immunoassays compared with the cytotoxicity assay for diagnosis ofClostridium difficile –associated diarrhea in dogs

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4 Robin L. P. Jump, Michael J. Pultz, and Curtis J. Donskey.

Vegetative Clostridium difficile Survives in Room Air on Moist Surfaces and in Gastric Contents with Reduced Acidity: a Potential Mechanism To Explain the Association between Proton Pump Inhibitors and C. difficile-Associated Diarrhea?

Antimicrob Agents Chemother. 2007 Aug; 51(8): 2883–2887

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5 Sturino J.M., Pokusaeva K., Carpenter R. Effective sequestration of Clostridium difficile protein toxins by calcium aluminosilicate. American Socjety For Microbiology

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