What percentage of dogs and cats experience colitis that is of sufficient concern
that they are taken to the vet?
is likely a
majority of dogs at some time in their lives will need
veterinary help due to large bowel disease (colitis).
Fortunately, most of these cases are transient bowel
irritations and recovery is rather prompt. In a very small
percentage of dogs, chronic, severe colitis is a problem.
In these, accurate diagnosis of the cause and implementation
of a treatment can be a challenge.
Probably the vast majority of house cats,
due to well-regulated dietary intake, never have colitis
problems needing veterinary intervention. Outdoor cats with
free access to hunt prey are more likely to have large bowel
flare-ups. Cats also have unique colon problems, especially
with constipation and a problem called megacolon where the
colon stretches and looses its intrinsic ability to contract
and expel the stool.
Is colitis more common in puppies (or
kittens), adult, or senior pets? Are the causes different at
different life stages?
Acute Colitis is a general term for any
inflammation or irritation of the large intestine (colon)
that suddenly flares up but lasts only a short time.
Chronic Colitis is a long term, difficult-to-treat, large
intestine disorder. Acute colitis is fairly common in
puppies and kittens less than ten weeks old and can be due to
a number of causes such as bacterial imbalance, intolerance
to the mother’s milk, or parasites. Most dogs and cats of
any age that eat proper diets and are well regulated
regarding food intake seldom experience colon trouble.
Probably the most common cause of adult acute colitis is
ingestion of a substance (such as a dead mouse, rotten
garbage, food contaminated with pathogenic bacteria) that
has a sudden impact on colon physiology.
How common is colitis from food
allergies? What approaches do you take to diagnose and
correct this problem?
Fortunately, colitis caused by food
allergies is rare in dogs and cats but does occur. It takes
lots of searching and testing by the veterinarian, and
patience exhibited by the pet owner, for the final diagnosis
of food allergy to be ascertained. Food intolerance, which
are different from food allergies, are a bit more common.
Often, these allergies and intolerances affect the small
intestine more than the colon, producing watery frequent
stools and even systemic effects; however, the large intestine receives whatever the
small intestine sends it and an apparent colitis may appear
to be present.
If the small intestine is inflamed and
upset (sometimes called small bowel enteritis), the abnormal
intra-intestinal contents may be difficult for the colon to
manage. Diagnosis of food allergy is attempted through
feeding trials with limited ingredient diets, with the
assistance of blood tests to measure immune factors to
certain food ingredients, and by ruling out all other
potential causes of colitis/enteritis. A true food allergy
can have diverse and intense effects on a dog or cat.
What parasites are the usual culprits
in causing colitis in dogs? What is the best course of
diagnosis and treatment?
Most intestinal parasites of dogs and cats
affect the small intestine, sparing the colon. Although not
classified as parasites, pathogenic (capable of causing
disease) bacteria are commonly associated with colitis.
Treatment depends upon making a correct diagnosis of the
individual animal’s problem.
Is immune-mediated colitis inherited?
What are the treatment options?Immune-mediated colitis, often called
IBD (irritable bowel disease), is a form of
autoimmune disease and results from the body’s abnormal
response to its own tissues. It may have inherited
predisposing origins. Much needs to be learned about
what triggers the invasion of apparently normal bowel lining
by immune cells that try to destroy the target bowel
tissues. Complex biochemical and hematological mechanisms
are at play with the result being inflamed, scarred, and
damaged bowel lining… and a sick patient. It is not
well understood what genetic factors are at work in these
autoimmune colitis patients.
Treatment varies as to the precise
diagnosis of the type, extent, and microscopic environment
of the individual patient’s affliction. Hypoallergenic
diets are often used, careful medication with cortisone is
common, and immune suppressing drugs may be needed.
What can owners do to prevent
constipation in cats?
The best thing is to be aware of any
discomfort when passing stool. If the cat vocalizes,
suddenly jumps out of the litter box, defecates in random
areas about the house… these are early warning signs that a
problem is developing.
A veterinarian should be consulted
before long-term colon pathology sets in. Dietary
modification with more or less fiber can be helpful.
Sometimes adding stool softeners every day can assist in
easier passage of hard stool. Enemas may be needed on
occasion, too, so that the stretching and thinning of the
colon wall won’t result in a flaccid, stretched megacolon
Can pet owners
prevent colitis in their pet dogs and cats?
It is always best to feed only the highest quality pet
food! It may be a bit more expensive than “ordinary” foods
but high quality foods are more efficiently digested, have
less non-nutritive fiber, provide a better level of
nutrition to every cell in the body and impart better
resources for competent immune system function. Then be
proactive regarding any difficulty the pet may have
defecating. Alert your veterinarian if episodes of
constipation or loose stool occur. And try to keep the pet
on a consistent dietary plan of high quality food fed in
amounts that do not promote an overweight body condition.
Barium contrast radiographs help to
display various abnormalities of the colon
This abdominal radiograph of a dog
reveals constipation which usually does not occur
with colitis or IBD
Gas filled and segmented pattern to
the descending portion of the colon is seen in this
radiograph and the colon wall appears thickened
A common sign of colitis in dogs and
cats is straining to pass stool even when the colon
A number of laboratory tests need to
be done to help sort out the cause of the IBD or
Long term IBD and colitis can lead to
malabsorption of nutrients, loss of nutrients
and subsequent loss of normal body fat and muscle.
Eliminating outside the litter box is
a sure sign of discomfort and stress
Tissue biopsy of
colon tissue often will be the key to establishing a
definitive diagnosis of the IBD/colitis problem.
The words "colon", "large intestine" and
"large bowel" are interchangeable. This portion of the
digestive tract is the last segment to retain the digested
food that has been processed by the stomach and small
intestine. In dogs and cats the small intestine has a
smaller diameter but a four-times greater length than the
The colon is
reabsorption of water from the feces
decreasing the fecal volume
colonic bacterial activity
bacterial vitamin generation
firming the feces
temporary storage of feces
The most obvious signal of colitis is loose stool,
mucus and an increased frequency of passage. The dog often
strains to pass small amounts of stool and may appear to be
Note: Weight loss is not a common finding unless long term
(chronic) colitis is present. Rapid weight loss associated
with loose stool usually means the small intestine is
involved. Red blood, rather than black, tarry blood
associated with small intestine bleeding, is indicative of
The loose stool commonly seen in colon disorders is due to lack of proper
reabsorption of water from the feces. This can be due to:
A hyperactive colon is contracting too frequently and the feces don't spend enough
time in the colon to have the water reabsorbed. Dehydration
becomes a serious consideration.
Impaired reabsorption of the water through the colon wall and
then back into the body. Dehydration becomes a serious
History - It is very important to observe and describe
accurately factors such as the
type and frequency of stool, the dog's environment, diet,
stress factors, straining, etc.
Laboratory analysis - fecal exams for parasites, undigested
Colonoscopy - Direct visual exam by a specialist can be very
Biopsy - Often in chronic colitis the biopsy provides the
final diagnosis regarding the cause. This requires an anesthetic
and surgical procedure, therefore, other modes of diagnosis
and treatment are employed first. Barium enema and X-ray
imaging can be helpful as a method
of diagnosis and better prepares the surgeon if an
exploratory abdominal surgery is planned. Surgery for direct visualization
of the colon provides direct access to the tissues for
hands-on inspection and for obtaining biopsy specimens for
The treatment depends of course upon the cause.
Dietary changes may be required so various ingredients can
be eliminated or added to keep the colonic environment
consistent. Whipworms must be ruled out even if fecal samples are
negative. Antibiotics, proper worming, and adding or
removing fiber from
the diet are employed with varying success. This is one
disorder that requires close cooperation with your vet, good
record keeping, and patience.
Causes of Colitis:
Parasitic - Whipworms reside in the upper colon (unlike
hooks and rounds); protozoan parasites in some areas of the
country are caused by Giardia, Trichomona, Amebia and
Foreign Body Colitis - We've all seen the dog that eats
grass and straw. This indigestible fiber really irritates
the large bowel. Any dog with pica is a candidate for
Bacterial Colitis - Often is caused by Salmonella and
Inflammatory Bowel Disease -
Known as IBD, this is an important
group. This disorder is due to an invasion of the wall of
the large bowel by certain types of body cells. Eosinophils
and plasma cells are commonly involved.
Irritable Bowel Syndrome - Usually has a neurological or
psychological origin. It is seen often in the
hyper-excitable dog that is stressed, overworked, or
Typhlitis - Inflammation of the cecum which is a dead-end
pocket branching from the intestinal tract where the small
and large intestine join. The medical term for this area is Ileoceco-colic
Cancer - The two most common types are
infiltrative lymphosarcoma and