Bladder Stones

Bladder stones are called uroliths or calculi, and are rock-like collections of minerals that form in the bladder. There may be a single stone, a few, or many the size of grains of sand.

Why do bladder stones form?  
Bladder stones form when the urine is oversaturated with minerals, there are several factors that can lead to their formation.

Diet, metabolic illness, genetic factors, and bacterial infections of the urinary tract can predispose to bladder stone formation.

There are several different types of bladder stones and since different types require different treatment it is important to determine the type present.

What problems do bladder stones cause?

  • The two most common signs are blood in the urine and straining to urinate.
  • Irritation of the lining of the bladder and lower urinary tract causes bleeding, inflammation, and pain.
  • Stones can also block urine passage, requiring emergency attention.

Dogs may also urinate small amounts frequently, sometimes only passing a few drops at a time, and can urinate in inappropriate places such as in the middle of the kitchen floor.

This is an x-ray of a 3.8kg terrier, note the bladder is full of stones

This is an x-ray of a 3.8kg terrier, note the bladder is full of stones

How are bladder stones diagnosed?
Some large stones can be felt through the abdominal wall, but X-rays are required to diagnose their presence.  Ultrasound examination will also detect bladder stones.

Blood and urine tests will also be taken to investigate the condition and determine the best method of treatment

How are bladder stones treated?  
Some stones can be dissolved medically by feeding a special diet. The diet must be fed exclusively and the process can take up to a few months.
The other option is surgical removal. There are many factors that influence the best approach to treatment.
Antibiotics are used for any bacterial infection.


The stones after being surgically removed

The stones after being surgically removed

Do bladder stones recur, and can they be prevented?

The recurrence rate is 20 to 50% so preventative therapy is important. Once the stones have been surgically removed or dissolved then most types of stones can be prevented from recurring by adhering to a prescription diet. Changing the diet has a number of beneficial effects: it reduces the concentration of minerals that are an issue, alters the pH of the urine and in doing so creates a less hospitable environment for bacteria to grow.