Overview:

Colitis is the inflammation of the lining of the colon (large intestine). It may be chronic, symptoms have been present for 14 to 21 days, or acute (sudden onset).

The colon is responsible for extracting water from the feces & storing fecal matter prior to evacuation (bowel movement).

Inflammatory bowel diseases are classified according to the type of inflammatory cell infiltrating the gastrointestinal wall. Lymphocytic-plasmacytic enterocolitis is the most common form of IBD. Lymphocytes (a type of white blood cell) & plasma cells (antibody producing cells) are the predominant type of inflammatory cells present in the mucosa of the small & large intestine. Eosinophilic Enterocolitis is the second most common form of IBD, eosinophils may be found in the stomach, small intestine or colon, Granulomatous (Regional) Enteritis in which macrophages are found in the lower small intestine & colon.

If the inflammation is restricted to the large intestine it is referred to as colitis, if the small intestine is involved it is referred to as enteritis & if both the large & small intestine are involved it is referred to enterocolitis, if the stomach is involved it is referred to as gastritis. [1]

What causes colitis in cats?

There are several causes of colitis including;

• Certain bacteria (Salmonella and Campylobacter), viruses, fungi.
• Dietary allergy or intolerance
• Parasites (intestinal worms, protozoal)
• Pancreatitis
• Cancer
• Dietary indiscretion (eating garbage, spoiled food, human foods, foreign object)
• Stress

What are the symptoms of colitis in cats?

The most obvious sign of colitis is diarrhea, possibly outside the litter tray because of the 'urgency' to go. The stool is often soft or watery & may contain blood or mucus. Other symptoms may include;

• Straining (tenesmus) in the litter tray causing discomfort
• Frequent defecation
• Diarrhea (the stool may start out normal but finish off loose or watery)
• There may be blood or mucus in the stool
• Reduced appetite
• Constipation
• Vomiting
• Dehydration
• Abdominal pain
• Chronic colitis can lead to weight loss
• How is colitis diagnosed?

Your veterinarian will perform a physical examination of your cat & obtain a medical history, including symptoms you have noticed. Your veterinarian may be able to determine a cause depending on how the colitis has presented. Was it acute (sudden onset), chronic (lasting several weeks) or episodic (comes & goes).

• Fecal test for bacteria, nematodes (worms) & Giardia.
• Complete blood count. Most cases will reveal a normal CBC but some cats may have become anemic. Higher numbers of white blood cells may be observed.
• Chemistry profile (biochemistry profile) to evaluate for diabetes mellitus, liver disease, renal disease.
• Urinalysis
• X-Rays/Ultrasound don't help diagnose colitis but are useful to rule out other medical conditions such as cancer.
• Colonoscopy & biopsy to determine the type if inflammatory cell present, check for cancer.
• Feline trypsin-like immunoreactivity (fTLI) to evaluate for pancreatitis.
• FIV & FeLV tests may suggest if a secondary disease is present.
• Total T4 (TT4) to evaluate for hyperthyroidism as diarrhea can be a symptom.

How is colitis treated?

• If a cause can be identified then elimination of the cause.
• A highly digestible, low fat diet containing a novel protein should be instituted.
• If the colon is affected, a high fibre diet should also be provided.
• De-worming.
• Antibiotics.
• Anti-inflammatory medications.
• If necessary, fluids for dehydration.