What are bladder stones in dogs?

Understanding Bladder Stones in Dogs

Bladder stones, sometimes called uroliths or cystic calculi, are solid mineral masses that form inside a dog's urinary bladder. These stones can range from tiny grains resembling sand to larger, gravel-like pieces. Some dogs may have just one large stone, while others might develop several of different sizes at the same time.

How Do Bladder Stones Form?

The process begins when minerals naturally present in your dog’s body aren’t properly processed by the urinary system or when these minerals become too concentrated in the urine. Over time, these minerals crystallize—especially if factors like urine pH, diet, low water intake, infections, or genetic predispositions come into play. The crystals then combine with organic material and harden into stones.

While stones can form anywhere along the urinary tract—including kidneys, ureters, bladder, and urethra—they’re most often found in the bladder or urethra.

Types of Bladder Stones

• Struvite (magnesium ammonium phosphate): The most common type in dogs (especially females), often linked to urinary tract infections (UTIs) that raise urine pH.
• Calcium Oxalate: More typical in male dogs and certain breeds; forms in acidic urine and can’t be dissolved by diet.
• Urate: Seen mostly in Dalmatians or dogs with liver shunts due to abnormal uric acid excretion.
• Cystine: Caused by inherited kidney transport defects; usually affects males between ages three and six.
• Silicate: Rare; associated with dietary silicate intake and seen more often in some breeds.

Which Breeds Are at Risk?

Certain breeds like Dalmatians, Miniature Schnauzers, Bulldogs, Bichon Frises, Yorkshire Terriers, Lhasa Apsos, and Cocker Spaniels are more prone to specific types of bladder stones due to genetics.

Symptoms: What to Watch For

• Difficult or painful urination (straining)
• Blood in the urine
• Peeing small amounts frequently
• Painful urination or accidents indoors
• Licking at genital area
• Abdominal discomfort
• Lethargy or vomiting (in severe cases)

If your dog is straining but not producing urine or only dribbling small squirts, this could signal a dangerous blockage—seek emergency veterinary care immediately. Obstructions can quickly lead to serious complications like bladder rupture or kidney injury.

Main Causes and Risk Factors

• Bacterial UTIs altering urine pH (especially for struvite stones)
• Diets high in magnesium, phosphorus, calcium, protein, oxalate, or silicates
• Poor water intake leading to concentrated urine
• Liver shunts (for urate stones)
• Certain medications or metabolic disorders like Cushing’s disease or hyperparathyroidism

Diagnosis: How Are Stones Found?

1. A veterinarian will start with a physical exam—sometimes they can feel stones during abdominal palpation.
2. A urinalysis: Looks for crystals, blood cells, abnormal pH levels, and infection signs.
3. A urine culture: Identifies bacteria if infection is suspected.
4. Blood work: Checks kidney/liver function and mineral levels.
5. X-rays: Reveal radiopaque stones (like struvite/calcium oxalate).
6. Ultrasound: Detects radiolucent stones (urate/cystine) and assesses the urinary tract for blockages.

If a stone is removed or passed naturally, it’s sent for laboratory analysis—knowing its composition helps guide future prevention strategies.

Treatment Options for Bladder Stones

1. Surgical Removal (Cystotomy): The fastest way to remove large/multiple/obstructive stones. Recovery is typically quick. If the urethra is blocked (more common in males), other procedures like urethrotomy may be needed.
2. Urohydropropulsion: For small stones—a catheter flushes saline through the bladder to force out stones via the urethra. Imaging checks confirm complete removal afterward.
3. Lithotripsy: Uses laser energy to break up stones inside the bladder/urethra so they can pass naturally or be retrieved. This option isn’t always available everywhere.

Certain stone types—like struvite and urate—may dissolve with special prescription diets designed to alter urine pH/mineral content while boosting water intake. However, calcium oxalate/cystine/silicate stones usually require surgical removal since they don’t dissolve with diet alone. Antibiotics may be necessary if infection is present; medications like allopurinol help prevent some types of stone recurrence.

Aftercare & Prevention Strategies

• Feed only prescribed therapeutic diets if recommended by your vet—no treats/supplements without approval!
• Encourage hydration using canned food or adding water to meals.
• Sustain regular bathroom breaks to flush out the bladder frequently.
• Treat any UTIs promptly; manage underlying health issues diligently.
• Your vet will schedule follow-up visits for urinalysis/imaging since many types of stones tend to recur over time.
• If you notice any trouble peeing or blood in your pet’s urine again—don’t wait! Get them checked right away as complications can escalate fast if untreated.

A Quick Reference Table of Common Stone Types: