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What are the Causes of Bladder Stones in Dogs

Bladder stones in dogs are obstructions of the urinary tract that form from a variety of buildups.

These obstructions are painful and can lead to fatal health problems if not passed. Genetics, diet, and breed are all factors in their formation.

Our very own Miss Molly suffered from a severe case of bladder stones which required surgery. We will talk more about her story as well as learn what causes them, their symptoms, and treatment options.

What are the Causes of Bladder Stones in Dogs

What are Dog Bladder Stones?

Bladder stones, medically known as urinary calculi, are tiny bladder stone formations from minerals that obstruct the kidneys, ureters, bladder, and urethra.

There are different types of bladder stones. They’re differentiated by their composition or what they are made of.

Struvite bladder stones, for instance, form from magnesium ammonium phosphate.

Other stones form from calcium oxalate, calcium phosphate, cystine, ammonium urate, and several other sources.

Stones crystallize around a single irritant, called a nidus, which grows in size inside the urinary tract.

What are the Symptoms of a Dog with Bladder Stones?

Dogs with bladder stones experience pain and can be very uncomfortable if sizable stones block or cause an obstruction of urine flow.

The most common signs of bladder stones include pain or straining while urinating, blood in the stream, and frequent urination in small quantities.

Bladder stones can also cause abdominal pain.

However, some dogs show little or no signs and the stones are only found when a vet examines the animal’s abdomen during a physical examination or through abdominal X-rays.

Female dogs and smaller breeds are at higher risk than male dogs and larger breeds due to their shorter urethras.

When Miss Molly developed bladder stones, she would stop and try to urinate but only a dribble was coming out. She would take a few more steps and repeat the process. She spent her whole time outside “trying” to urinate. Every time you looked at her, she was squatted down attempting to use the bathroom. I can only imagine how miserable she was! This triggered an urgent vet appointment to see what was going on.

What Causes a Dog to Get Bladder Stones?

Predisposing factors or a genetic predisposition play a large role in bladder stones.

Some animals’ genes cause them to produce higher levels of substances that are precursors to bladder stones.

Dalmatians and English bulldogs appear to have a genetic defect that results in urate stones, a form that only results from liver shunts in other breeds.

Urine pH also plays an important part in the formation of bladder stones.

Struvite stones form in alkaline urine while those such as calcium oxalate stones thrive in acidic urine.

Urine pH is largely influenced by diet. High amounts of magnesium, ammonium, and phosphate often come from high-protein diets.

Bacterial infections affect urine pH and facilitate the crystallization of struvite stones.

Moreover, a dog’s body produces more substances that include materials for bladder stones when trying to fight off an infection.

Small black dog getting an ultrasound at the vet.

How are bladder stones diagnosed?

Diagnosing bladder stones is not always straightforward as the clinical signs can be similar to those of an uncomplicated bladder infection or cystitis.

In some cases, the stones may be palpable through the abdominal wall, but this is not always possible due to their size or inflammation of the bladder.

To accurately diagnose bladder stones, diagnostic tests such as imaging tests like X-rays or ultrasound are often used.

These tests allow for visualization of any stones present in the bladder and can help determine their size and composition.

A urine sample for analysis and urine culture may also be performed to look for crystals that could indicate the presence of bladder stones.

If needed, further testing such as cystoscopy may be recommended to confirm the diagnosis and provide additional information about the location and type of stone present.

When our dog Miss Molly started having trouble with bladder stones it was first diagnosed as a bladder infection. They did an ultrasound but because of her size (she’s a “healthy” girl) and position on the table, the stones were missed on the first ultrasound test. She was put on antibiotics and sadly after two different rounds of antibiotics, she was still having the same problem. They did ANOTHER urine culture and a VERY detailed ultrasound. Poor girl had a tremendous load of stones that the vet could not believe were missed the first go-around. She was immediately scheduled for surgery to have them surgically removed because there was no more time to waste. Once her procedure was done to rid her of the stones, she was up to being active and acting like her old self again.

Our Heeler-Pit Bull Mix, Molly, not feeling good due to bladder stones.
Our Heeler-Pit Bull Mix, Molly, not feeling good due to bladder stones.

How is a Dog with Bladder Stones Treated?

Treatment for bladder stones depends on their size and location.

About 85 percent of stones are found in the bladder itself.

The gentlest method of treatment is through water consumption.

This is done by increasing the amount of water in the dog’s diet through the swapping of dry for wet food.

One option is urohydropulsion. This is a process by which the bladder is filled with saline via a catheter and is then emptied.

In some cases, it may be necessary to surgically remove bladder stones.

The procedure is called a cystotomy.

These methods are more common with calcium oxalate stones.

Struvite stones (one of the types of stones) can often be dissolved through dietary dissolution when recommended by a veterinarian.

These diets can last as long as four months.

The treatment of urate stones also involves special diets.

How to Prevent Bladder Stones in Dogs?

The best way to prevent future stones is to maintain a healthy diet and water intake.

This includes providing your pet with plenty of fresh water, as well as a balanced diet that is appropriate for their age, breed, and activity level.

It is also important to keep up with regular veterinary check-ups and urine tests to ensure that any changes in the urine pH or presence of bacteria are detected early on.

Dog Breeds Predisposed to Bladder Stones

Certain breeds of dogs are more prone to developing bladder stones than others.

These include small breed dogs such as Yorkshire Terriers, Shih Tzu, and Miniature Schnauzers.

Other breeds that may be predisposed include Dalmatians, Bulldogs, and Bichon Frise.

It is important to note that ANY DOG can develop bladder stones regardless of their breed or size


The elimination or reduction of urinary tract infections is especially important in the prevention of recurring struvite stones.

Bladder stones in dogs can be considered a medical emergency that warrants emergency treatment as a urinary obstruction can lead to kidney shutdown and death.

Therefore, they must be watched carefully and dealt with in a timely manner.

Regular checkups are an excellent prevention strategy as well as a constant supply of clean water.

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