Inflammatory Bowel Disease
(IBD) in Dogs
Overview:
Inflammatory bowel disease
is the leading cause of chronic
vomiting
&
diarrhea
in dogs. It is not a disease in itself but is the name
given to a group of disorders caused by to the infiltration
of inflammatory cells (white blood cells) in the mucosa
of the gastrointestinal tract. Dogs of any age can be
affected although middle aged & older dogs are more
susceptible than young ones.
Both the upper &
lower intestinal tract can be affected and in some cases
both.
IBF's 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]
Persistent
inflammation results in fibrosis (formation of scar-like
'fibrous' tissue), poor digestion & absorption may
also result.
What
causes IBD in dogs?
The cause
of IBD is still unknown although evidence suggests that
it could be the result of certain bacteria, dietary allergy
or intolerance, genetic influence & parasites causing
dogs to produce antibodies that attack their own digestive
tract. It has also been suggested that there is an inappropriate
immune response to the natural flora in the intestine.
What
are the symptoms of IBD in dogs?
Clinical
signs vary depending on the region affected and may
include;
-
Diarrhea
-
Lethargy
-
Loss
of appetite (anorexia) or
increase in appetite (polyphagia)
-
Vomiting
-
Weight
loss
How
is IBD diagnosed?
Your veterinarian
will perform a physical examination of your dog upon which
may show weight loss, dehydration, thickened intestinal
loops upon palpitation. He will also obtain a medical
history from you. There are many other conditions which
may produce similar symptoms to IBD so your veterinarian
will wish to rule these out. Other conditions include
various parasites, neoplasia, hyperthyroidism, diabetes,
salmonellosis, campylobacteriosis, chronic renal failure,
liver disease, chronic pancreatitis.
Tests performed
may be:
-
Complete
blood count. Most cases will reveal a normal CBC
but some dogs may have become anemic. Higher numbers
of white blood cells
may be observed.
-
Biochemical profile to evaluate for diabetes
mellitus, liver disease, renal disease.
-
Total
T4 (TT4) to evaluate for hyperthyroidism.
-
Urinalysis
-
Fecal
examination should be performed to evaluate for worms
& Giardia.
-
X-Rays/Ultrasound
don't help diagnose IBD but are useful to rule out other
medical conditions such as cancer.
-
The
only definitive way to diagnose IBD is via biopsy/histopathology
of the intestinal tract. Increased numbers of plasma
cells, lymphocytes, eosinophils, and neutrophils are
seen in the intestinal wall. The types of cells present
will provide a diagnosis of which type of IBD the dog
has.
Grading
IBD:
Once a
diagnosis has been made the IBD will be graded into mild,
moderate or severe.
How
is IBD treated?If a
cause can be identified then elimination of the cause.
Diet:
-
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.
Drugs:
-
Corticosteroids
- Prednisone is the drug of choice (as well as
dietary
therapy) for all types of IBD. These drugs have anti-inflammatory
& immunosuppressive properties.
-
Antibiotics
such as metronidazole sometimes used in conjunction
with dietary therapy to help manage IBD.
-
Other
immunosuppressive drugs which may be useful in some
cases of IBD. Azathioprine is one such drug but may
have side effects & is therefore only used in
refractive (unresponsive to diet &
corticosteroids)
IBD. Dogs on this drug should have a CBC every week
for the first month & every 2-3 weeks while the
dog is on the drug.
-
Sulfasalazine
is the drug of choice for lymphatic-plasmacytic colitis.
Please
note:The
medical articles on this site have not been written
by a veterinarian & should not be considered a replacement
for a veterinarian visit. The articles are provided
for informative purposes only.
Always
seek immediate veterinary advice for any problems (health
or behavioral) in your pets.
While
great care has been made in the creation of these articles,
we cannot guarantee the accuracy or omissions on these
pages. If in any doubt whatsoever, seek professional
medical advice.
Please note:
The medical
articles on this site have not been written by a
veterinarian & should not be considered a replacement for a
veterinarian visit. The articles are provided for
informative purposes only.
Always seek
immediate veterinary advice for any problems (health or
behavioral) in your pets.
While great
care has been made in the creation of these articles, we
cannot guarantee the accuracy or omissions on these pages.
If in any doubt whatsoever, seek professional medical
advice.
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