Bladder stones, more correctly called uroliths, are rock-like
collections of minerals that form in the urinary bladder. They may
occur as a large, single stone or as dozens of stones the size of
large grains of sand or pea gravel. Stones that form in the bladder
may pass into the uretha. All dogs can develop bladder stones.
Stones in the bladder eventually cause painful urination and blood
in the urine. Your dog may cry in pain, especially if pressure
is applied to their stomach..
The two most common signs of bladder stones are hematuria (blood
in the urine) and dysuria (straining to urinate). Hematuria occurs
because the stones irritate the bladder wall, causing bleeding from
its surface. Dysuria occurs when stones obstruct the passage of
urine out of the bladder. Large stones may cause a partial
obstruction at the point where the urine leaves the bladder and
enters the urethra; small stones may flow with the urine into the
urethra and cause an obstruction in this area.
Most bladder stones are visible on radiographs (x-rays) or an
ultrasound examination. These procedures are performed if stones
are suspected. This includes dogs that show unusual pain when the
bladder is palpated, dogs that have recurrent hematuria and dysuria,
or dogs that have recurrent bacterial infections in the bladder.
Stones that pass spontaneously and those that re removed surgically
should be analyzed, if possible, since the composition of the stone
influences the treatment of any remaining and future stones.
There are several types of bladder stones. One of the most
common is called struvite. These stones consist of Magnesium,
Ammonia, and Phosphorus. Another is the urate stone. These are
commonly found in Dalmatians that have a genetic enzyme deficiency
that allows urates to form in the bladder. Still another type is the
oxalate stone. There are other less common kinds of stones.
Bladder stones are
sometimes an indication of Liver-Shunt. Many Yorkie shunt
puppies are diagnosed with bladder stones prior to a Liver-Shunt