Colitis

Colitis refers to inflammation of the colon (e.g., large
intestine) with any of a variety of causes. Colitis is a
relatively common problem in pets and may be caused by reactions
to food, gastrointestinal parasites, bacterial or fungal
infections, benign infiltrative diseases (such as inflammatory
bowel disease), and even neoplasia (cancer).

The most common symptoms of colitis include straining to
defecate, bright red blood on the stool, fecal mucus, and
increased frequency of defecation. Most animals are alert,
active, and have normal appetites in spite of having colitis.
Occasionally, they have diseases affecting both the small
intestine and colon, which may cause vomiting, alterations in
appetite, and/or weight loss.

Diagnosis of colitis is based on the patient’s history and
findings of the physical examination by your veterinarian and
selected diagnostic tests. Puppies and kittens are particularly
prone to acute colitis caused by dietary indiscretion (eating
garbage), parasites, and bacterial infections, which may be
spread from animal to animal. Most of these disorders cause
abrupt symptoms prompting veterinary attention.

Parasites are easily diagnosed by your veterinarian, who can do
so by examining fecal material under a microscope. Rectal swabs
for cytologic examination or bacterial fecal cultures may also
be recommended.

Other diseases, such as fungal infections (e.g.,
histoplasmosis), inflammatory bowel disease, and neoplasia,
occur mostly in adult animals and are characterized by symptoms
that have been present for several weeks to months.

These animals usually require hospitalization and a more
in-depth diagnostic evaluation to confirm a diagnosis. Careful
rectal examination is performed in all animals and may provide
important clues to the cause of inflammation.

Therapeutic trials in animals suspected of having parasitic or
dietary causes of colitis are reasonable. Some parasites (such
as whipworm infestation in dogs) are difficult to detect. Your
veterinarian may treat your pet with medication to kill this or
other suspected parasites. If bacterial infection caused by
Clostridium perfringens is suspected, treatment with an
antibiotic is often useful.

Pets that have dietary causes of colitis usually respond
favorably to being fed “bland” or hypoallergenic diets. These
nutritionally complete diets are highly digestible and reduce
the workload of the gut. Fiber supplementation is also
beneficial in promoting healing and repair of colonic tissue. A
variety of prescription foods or recipes for homemade diets that
are appropriate for your pet are available from your
veterinarian.

Animals that fail to respond to symptomatic therapy and those
having chronic symptom require additional diagnostic testing.
These tests may blood work, urinalysis, radiographic imaging
procedures, and tissue biopsy. Endoscopic examination of the
colon (e.g., colonoscopy, which is an examination of the inside
of the colon with a scope and light) with mucosal biopsy
provides the most definitive diagnosis in most cases.

Your pet may require hospitalization before the procedure for
bowel cleansing. The colonoscopy is performed while your pet is
anesthetized or sedated. The results of endoscopic biopsy will
guide treatment recommendations by your veterinarian and provide
useful information about the likelihood of cure or recurrence.

Regardless of the cause, dietary modification with a
hypoallergenic diet and fiber supplementation are beneficial for
most dogs and cats with chronic colitis.

The above is general veterinary information. Do not begin
any course of treatment without consulting your regular
veterinarian. All animals should be examined at least once every
12 months.