Colonic or Rectal Inflammation in Cats

PetMD Editorial
By PetMD Editorial on Jan. 13, 2009
Colonic or Rectal Inflammation in Cats

Colitis and Proctitis in Cats

Histiocytic ulcerative colitis is a bowel disease which causes the lining of an animal's colon to thicken, with varying degrees of ulceration and tissue loss to the superficial lining. The thickening is due to the infiltration of various cells in the layers under the lining. When the colon becomes inflamed, there is a reduction in the colon's ability to absorb water and store feces, leading to frequent diarrhea, often with mucus and/or blood. Proctitis, conversely, is inflammation of the anus and lining of the rectum.

Inflammation of the colon and rectum can occur in any breed of cat.


Symptoms and Types


Some of the symptoms that may indicate inflammation of the colon or rectum are frequent bowel movements with only a small amount of stool, and prolonged straining after a bowl movement, as though the cat needs to pass more. Inflammation can also cause the stool to vary in consistency, from semi-formed to fluid, to diarrhea. Evacuating stool can further irritate the inflamed tissue of the colon and rectum, causing it to tear. As a result, chronic diarrhea will often have mucus and/or blood in it.


Irritation and ulceration of the colon can also lead to responsive vomiting and weight loss as a result of decreased appetite.




There are a variety of possible causes for this condition. The source can be from intestinal or rectal parasites; bacterial infection; fungal infection; or an algae infection (water based). It may also result from swallowing a foreign object or abrasive material, causing trauma to the intestines.


An otherwise healthy system can occasionally react to infection or disorder by retreating into itself. In some cases, urine or waste products will reverse into the body system instead of vacuating, resulting in abnormal amounts of waste products entering into the bloodstream. Urea, a waste product in urine, is one of the potentially harmful products that can enter the bloodstream. This can cause other problems for your cat's body as well, but one of the possible indicators of waste back-up is inflammation of the intestinal tract.


An inflamed intestinal tract can also be an indicator of inflammation in other organs. For example, long-term inflammation of the pancreas (pancreatitis) will irritate the intestines. Inflammatory or immune disorders, diet, and swallowing foreign objects can also affect your cat systemically, leading to inflammation of the colon and rectum.


Perhaps less worrisome than an immune disorder, but a critical consideration nonetheless, is the possibility that the condition is the result of allergies. If an allergy is presenting itself through inflammation of any organ or system, it will be important to pinpoint the source of the allergy. Reactions to allergens tend to intensify with further contact, sometimes with fatal results.






If your cat is dehydrated from chronic diarrhea, it will need to be hospitalized for intravenous rehydration. If the inflammation is sudden and severe, your veterinarian may have you withhold food for 24 to 48 hours, to allow your cat's colon to relax. Meanwhile, if chronic inflammation and scar tissue has formed in the colon, surgical removal of the most severely scarred segments may be required. Inflammation from a fungal infection may also require surgery.


Prescriptions for medications will be based on the cause of the inflammation. For example, if the inflammation is the result of whipworms or hookworms, anti-parasitic drugs will be prescribed. Anti-inflammatory and immunosuppressive drugs may be prescribed if the cause is an autoimmune reaction. Some types of colitis respond poorly to medical treatment; in these cases, surgery may be necessary. Consult your veterinarian as to your best option.


Home treatment will most likely be focused on diet. Your veterinarian may suggest a protein diet that is either prepared by you at home, or is a pre-packaged, store bought item. Supplementing with unfermented fiber, such as bran, may be used to increase fecal bulk, improve muscle contractions in the colon, and draw fecal water into the feces. On the other hand, some fermentable fibers may be beneficial. The fatty acids produced by the fermentation may help the colon heal and restore normal bacteria in the colon. Some fibers, such as psyllium, may act as laxatives, and may not be the best remedy for a condition that causes diarrhea, so it is important to consult with you veterinarian before beginning any course of treatment at home.


Living and Management


Your veterinarian will need to see your cat for follow-up exams, at least for a while. Some of these check-ups may be done over the phone, as you can describe your cat's progress to the doctor. If medications are prescribed, you will need to take care in following your veterinarian's full instructions.




To prevent recurrent inflammation of the colon and rectum, avoid exposure to other animals, contaminated foods, and moist environments. Avoid sudden changes in diet, as well. Repeated recurrences of inflammation can be expected when it is related to autoimmune conditions, though this is not always the case.

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