Diarrhea-causing Bacterial Disease in Horses

By PetMD Editorial on Oct. 2, 2008

Intestinal Clostridiosis


Intestinal clostridiosis is a disease which causes severe diarrhea in horses. It was not made official or researched much until the 1970s, when Swedish and American workers came across the disease and gave it its name. Intestinal clostridiosis is mainly associated with horses under a great deal of stress due to antibiotic treatments or a recent surgery. But being that the disease can affect horses of all types, ages and health conditions, it is important to be aware of its symptoms




A horse with intestinal clostridiosis will be reluctant to drink. It may stand by the water, not drink, and yet be visibly thirsty. Its mucous membranes -- especially near the anus -- become congested and dark red in color. Some other common symptoms for the disease include:


  • Depression
  • Weakness
  • Inclination to lay down or recline
  • Severe diarrhea (i.e., projectile diarrhea, foul-smelling feces, liquid feces)




The overgrowth of the bacteria Clostridium perfringens and C. difficile in the intestines is known to cause the disease, though the reasons for the overgrowth have yet to be determined. There have been, however, associations made between intestinal clostridiosis and an antibiotic called tetracycline; a stressful surgical procedure is another theorized factor for the disease.




The symptoms for intestinal clostridiosis may indicate a variety of equine diseases and afflictions. For this reason, an examination by your veterinarian of the horse's mucous membranes, as well as blood tests to confirm the bacteria, may be needed to make a positive diagnosis.




Prompt treatment is paramount when dealing with intestinal clostridiosis, as it can be fatal when it is left untreated for too long. There are numerous methods of treatment that a veterinarian may seek, but the main method of treatment involves administering intravenous (IV) fluids to the horse in large amounts. There has also been some research that suggests that sour milk is effective in eliminating the bacteria. Consult your veterinarian before attempting this. Flunixin melamine is another treatment that may be utilized, one that is used to combat the toxemia that tends to develop as a result of intestinal clostridiosis.


Unfortunately, despite aggressive treatment, many horses do not survive intestinal clostridiosis. The best methods of treatment are those that implemented quickly after the horse has been infected with the bacterium.

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