Page 773 - Problem-Based Feline Medicine

34 – THE CAT WITH SIGNS OF LARGE BOWEL DIARRHEA 765

both for effective therapy to be initiated and for pro-
INTRODUCTION
viding an accurate prognosis.
● The minimum database should include a CBC,
MECHANISM panel, urinalysis and complete fecal examination
(fecal flotation, direct, cytology).
The signs of large bowel disease include:
● Other diagnostic approaches that may be required
● Increased mucus.
include radiography, ultrasonography, endoscopic
● Hematochezia.
examination (especially for biopsy).
● Straining or increased urgency to defecate.
● Surgery on the colon is difficult, but in some neo-
● Soft to semi-formed feces.
plastic conditions or obstructive diseases, it will be
● Normal or increased frequency of defecation but
required.
not increased volume.
● It is rarely associated with weight loss or vomiting.
The colon responds to inflammatory conditions by pro- DISEASES CAUSING SIGNS OF
ducing increased amounts of mucus. LARGE BOWEL DIARRHEA
Blood streaks or fresh blood is also a common pre-
senting sign due to the proximity to the anus. IRRITANT (FOREIGN BODY) COLITIS**

Classical signs
WHERE
● Mucus- or blood-streaked, soft (semi-
Large bowel disease can result from disorders of ileo-
formed) stools.
cecal region, colon or rectum.
● History of ingestion of feathers, hair, bones
Historical and physical examination signs are impor- or other foreign objects (e.g. string, plants).
tant in localizing the problem to the large intestine.
Pathogenesis
Rectal examination is an especially important com-
ponent of the physical examination when evaluating Colitis and large bowel diarrhea that is caused by the
a cat for large bowel disease. presence of foreign objects (e.g. hair, bones, feathers) is
primarily due to the irritation of the colonic epithelium.

This results in motility disturbances and release of
WHAT
local inflammatory mediators that cause secretory or
Large bowel diarrhea can be caused by a variety of motility changes and ultimately, diarrhea.
infectious, dietary, metabolic, mechanical, neoplastic
Ingested hair, or a trichobezoar, is a common cause of
or idiopathic disorders.
irritant colitis in cats, especially in cats with long hair
● Acute large bowel diarrhea is often managed by
coats or with dermatologic disorders that result in
empirical therapy with anthelminitics, antibiotics
excessive grooming.
or a diet change.
● The most common causes of acute large bowel
diarrhea are parasites, dietary or infectious agents. Clinical signs
Chronic large bowel diarrhea is defined as the pres- Irritant colitis causes large bowel diarrhea that is inter-
ence of signs for more than 3 weeks. mittent and generally not severe in nature. Mucus- or
● Cats with chronic large bowel diarrhea should be blood-streaked, soft (semi-formed) stools are the
thoroughly evaluated to determine the diagnosis, most common presenting signs.