People often ask me questions about “Clostridium” in dogs and cats, with the impression that “Clostridium” is a specific disease. Actually, Clostridium is a large bacterial genus (a group of related bacteria), which includes species that range from harmless to deadly. Some of the more important species are described below:
Clostridium perfringens: This is a common bacterium that can be found in the stool of a large percentage of healthy animals and people. It is a common cause of “food poisoning” in people, and is probably an important cause of diarrhea in dogs and cats. Our understanding of the role of this bacterium in disease in dogs and cats is limited by the fact that it is found in so many healthy animals, so simply growing it from the stool of a diarrheic dog or cat does not prove that it is causing the animal’s illness.
Clostridium difficile: This bacterium is a very important cause of diarrhea (and more severe intestinal disease) in people, and is possibly an important cause of diarrhea in dogs and cats. It is rarely found in healthy adult pets, but is relatively common in puppies and kittens.
Clostridium botulinum: This bacterium produces the toxin that causes botulism, a potentially devastating disease that is very rare in dogs and cats. Botulism usually occurs following ingestion of food that has been improperly stored, in which C. botulinum has grown and produced its potent toxins.
Clostridium tetani: This bacterium produces the toxin that causes tetanus, which can occur in dogs and cats, however these species are relatively resistant to this disease. Tetanus usually occurs when a wound becomes contaminated with C. tetani from the soil, followed by growth of the bacterium and production of potent toxins.
Other clostridia: A large number of different species exist, and it is likely that many more clostridia are around but have not been identified and named. Many clostridia are part of the normal bacterial population in the intestinal tract. Some of these can probably also cause disease.
As you can see, “Clostridium” is more than a single bacterium or disease. An understanding of this concept, and the different disease-causing clostridia, is important. More information on Clostridium difficile can be found on the Worms & Germs Resources page.
Image: Photomicrograph of C. botulinum stained with Gentian violet. From CDC’s Public Health Image Library (PHIL), ID number #1979.