Bladder Stones in Dogs and Cats: Signs, Treatment and Prevention

By Dr Duncan Houston

Repeated trips to the litter tray or garden, blood in urine and straining can be signs of bladder stones. They can also look very similar to other urinary problems, so symptoms alone cannot identify the cause.

The first decision is whether urine is actually passing. A dog or cat repeatedly trying to urinate with little or no output needs emergency veterinary assessment, even if you think the problem is constipation.

Quick Answer

Bladder stones are mineral deposits that can irritate the bladder or block urine flow. Some stone types can dissolve with a carefully monitored veterinary plan; others require physical removal. Urine tests, imaging and laboratory stone analysis guide treatment and prevention. Inability to urinate is an emergency.

Why does the type of stone matter?

Stones develop when urinary conditions favour mineral precipitation. Genetics, infection, urine concentration and underlying disease can contribute. Crystals in a urine sample do not prove that a stone is present, and a stone can exist without visible crystals.

The Merck Veterinary Manual’s overview of urolithiasis explains why treatment depends on location and composition. A diet appropriate for one type may be unsuitable for another.

These are broad distinctions, not a way to choose treatment from the colour of urine. The Merck discussion of canine stones details the importance of infection control and recurrence monitoring.

How worried should you be?

What else can cause these signs?

Urinary infection, feline idiopathic cystitis, urethral plugs, prostate disease and urinary tumours can cause similar signs. Cats with cystitis may have no stones or infection. Kidney or ureteral stones are a different problem and need assessment based on their location. Avoid treating every urinary episode with leftover antibiotics.

When is this an emergency?

Do not wait if your animal cannot pass urine. Obstruction can damage the kidneys and cause dangerous electrolyte disturbances. Male cats and male dogs are particularly vulnerable because of their narrower urinary passage. Do not squeeze the abdomen, attempt catheterisation or wait for a diet to work.

What happens at the clinic?

The vet assesses comfort, hydration and whether the bladder is obstructed. Testing can include urinalysis, urine culture, blood tests, radiographs and ultrasound. Some stones show poorly on plain radiographs. Removed stones should be analysed because appearance and crystal type are not reliable substitutes.

Treatment may involve a dissolution diet with scheduled imaging, surgery, endoscopic removal, laser fragmentation or flushing suitable small stones under controlled conditions. The choice depends on size, location, anatomy, available equipment and the animal’s overall health. Dissolution must stop or change if obstruction or other complications develop.

Your practical action plan

1. Observe whether a genuine urine stream passes, without delaying urgent care.
2. Tell the vet about previous stones, diets, supplements and medicines.
3. Follow the prescribed diet consistently, including approved treats.
4. Encourage drinking through fresh water and an appropriate wet diet if recommended.
5. Attend imaging and urine rechecks even when signs disappear.
6. Keep a simple record of straining, accidents, blood and any treatment changes.

Common mistakes

• Assuming straining is constipation.
• Using urine acidifiers without knowing the stone type.
• Stopping follow-up because the urine looks normal.
• Mixing a therapeutic diet with unrestricted treats.
• Assuming all stones require antibiotics.

Preventing recurrence

Use a stone-specific nutrition and monitoring plan. Address infections and underlying conditions, maintain suitable body condition, provide regular toileting opportunities and support water intake. For cats, comfortable litter facilities and stress reduction help general urinary welfare but do not replace stone treatment.

Frequently Asked Questions

Can bladder stones dissolve?

Some can, but calcium oxalate cannot. Your vet must establish whether monitored dissolution is appropriate.

Are crystals the same as stones?

No. Crystals are microscopic particles; stones are larger mineral accumulations.

Will surgery prevent future stones?

Surgery removes existing stones. Recurrence prevention still matters.

Can a pet with stones look well?

Yes. A comfortable appearance does not rule out stones or future obstruction.

Confirm the cause, protect urine flow and make prevention specific to the stone. Those decisions matter more than choosing a generic urinary remedy.

For help understanding your animal’s care and preparing questions for your veterinarian, visit ASK A VET™.