What is cystitis?
"Cystitis" is an inflammation of the urinary bladder. It can refer to any
disease that causes inflammation of the urinary bladder.
What causes cystitis?
The most common cause of cystitis in dogs is an infection due to bacteria.
However, other causes include bladder stones, tumors or polyps in the bladder,
and sometimes congenital faults such as a diverticulum.
What are the signs of cystitis?
The most common sign seen by most owners is blood in the urine (hematuria).
In addition, many dogs show discomfort when urinating. They will strain and
spend several minutes passing only a small amount of urine. They may also urinate
more frequently than normal (frequency).
The signs will be determined by the specific cause of cystitis. Bacterial
infections usually cause hematuria and dysuria (straining to urinate). Bladder
stones are often very rough; they cause irritation to the bladder as they rub
against the bladder wall also creating hematuria and dysuria. Tumors or polyps
are usually not highly irritating to the dog's bladder, but they can bleed and
there is often mild straining to urinate. A diverticulum is a small pouch in
the wall of the bladder that usually causes haematuria and dysuria secondary
to the chronic bacterial infection that occurs. Bacteria often reside deep in
the diverticulum and are often impossible to remove without surgery.
How is cystitis diagnosed?
A history of haematuria, dysuria, and increased frequency of urination is strong
evidence of some form of cystitis. With such a history several tests are appropriate.
The first group of tests include urinalysis, urine culture, and examination
of the bladder by palpation (feeling with the fingers). A urinalysis
consists of several tests to detect any abnormalities in the constituents of
the urine. Routine tests include pH (degree of acidity or alkalinity ), Specific
Gravity (SG) which measures the strength of the urine and also tests for the
presence of substances such as blood, bilirubin and protein. In addition the
urine sediment is examined by special techniques to reveal any abnormal cells,
crystals or other materials which may be causing or contributing to the cystitis.
These tests are generally adequate to confirm the diagnosis but may not be
adequate enough to determine the exact cause. A urine culture determines
if bacteria are present and which antibiotics are likely to be effective in
killing them. This is appropriate because most cases of cystitis are caused
by bacteria which may be eliminated with selected antibiotics. Bladder palpation
is the "first" test for bladder stones, since many are large enough to be felt
by experienced fingers.
What is done if cystitis is present, but the culture is negative for bacteria
and stones cannot be felt?
This occurs in about 20% of cases. It is important that further tests are performed
so that a diagnosis can be achieved. These tests include:-
Plain radiographs (x-rays) which are taken to further evaluate the
bladder because many stones can be seen with this technique. However, the mineral
composition of some stones requires special radiographs, using contrast materials,
to be utilized. This technique can also be used to visualize bladder tumors,
polyps, or diverticula since these often do not show up on plain radiographs.
Ultrasound can be used. This technique uses sound waves to visualize
stones and also some tumors and polyps. It may also identify other abnormalities
of the bladder wall, including wall thickening. It can be performed without
sedation or anesthesia in a cooperative dog.
Contrast radiographs are taken when plain radiographs have failed
to help with the diagnosis. The bladder is filled with a negative contrast material
(usually air), which will visualize certain structures such as tumors or polyps
by outlining them. Sometimes further contrast studies involving the use of special
radiographic materials (positive contrast materials) also have to be used. These
techniques involve the use of sedation or general anesthesia
Dogs showing other signs of illness, such as fever, poor appetite, or lethargy,
should be evaluated for systemic diseases and bleeding disorders that may be
causing haematuria. For these dogs, a chemistry profile and complete
blood count (CBC) should be performed. If a clotting problem is suspected,
a bleeding profile may be needed.
How is cystitis treated?
Treatment depends on the cause. Bacterial infections can be treated successfully
with antibiotics. Some bladder stones can be dissolved with special diets; others
require surgical removal. Benign bladder polyps can usually be surgically removed,
but malignant bladder tumors are difficult to treat successfully. A bladder
diverticulum should be removed surgically.
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