Bladder Stones in Dogs: Types, Symptoms, Treatment and Prevention

Signs of Bladder Stones in Dogs

• Blood in the urine^2,1
• Straining or taking a long time to urinate²
• Peeing small amounts often, or accidents in the house^2,5

The same signs can come from a bladder infection, so testing is needed. See urinary tract infections in dogs.

Types of Bladder Stones

• Struvite: usually caused by a bladder infection with certain bacteria, and much more common in females.² Most can be dissolved with a special diet, plus antibiotics if there's an infection.^3,2
• Calcium oxalate: can't be dissolved and must be removed.³ Common in small breeds such as Miniature Schnauzers, Bichon Frises, Yorkshire Terriers, Shih Tzus and Lhasa Apsos, and more common in males.^6,5
• Urate: most common in Dalmatians, which inherit a gene that makes them prone, and in dogs with liver shunts (breeds prone to shunts include Yorkshire Terriers, Miniature Schnauzers, Maltese, Pugs and Shih Tzus).⁹ They can be hard to see on X-rays.^9,1
• Cystine: an inherited problem, almost always in male dogs that aren't neutered; Dachshunds and English Bulldogs are among the breeds affected.^8,1 Neutering may help in some forms.³
• Silica: uncommon, seen in breeds such as German Shepherds and Golden and Labrador Retrievers.¹

The only way to know the type for sure is to have a removed stone analyzed at a lab.¹⁰ In puppies under 6 months, most stones are struvite caused by infection.¹¹

Crystals vs. Stones

Crystals are microscopic and can form in a urine sample that is refrigerated or tested late. Stones can be present without crystals, and crystals can be present without stones, and the crystal type doesn't always match the stone.¹² Crystals alone shouldn't be used to diagnose stones.¹²

How Vets Diagnose Bladder Stones

• Urinalysis and urine culture to look for blood, crystals and infection^3,2
• X-rays: most stones larger than about 3 mm show up, but urate and some cystine stones are hard to see^13,1,9
• Ultrasound, which can find stones that X-rays miss¹
• Stone analysis after removal, which guides prevention^10,3

Treatment of Bladder Stones

• Dissolution diet: sterile struvite stones usually dissolve within 2 to 5 weeks on a prescription diet; infection-related stones also need antibiotics and can take longer.^3,2,7 Your vet will recheck with X-rays every few weeks. Small stones can pass into the urethra and block it, so watch for straining at any time.²
• Non-surgical removal: small stones can sometimes be flushed out through the urethra (voiding urohydropropulsion) or retrieved with a scope; larger ones can be broken up with a laser. Specialists prefer these less invasive options when they're available.^3,6
• Surgery (cystotomy): opening the bladder to remove the stones. It's often recommended for male dogs or when stones can't be dissolved.^1,2 X-rays or a scope after the procedure can check that no stones were left behind; leftover stones are a common reason stones seem to return quickly.^6,13
• Urate stones may dissolve with a low-purine diet plus medication, but not while a liver shunt is uncorrected.³

Preventing Bladder Stones From Coming Back

• More water: diluted urine is the most important step. Specialists aim for urine that's dilute (specific gravity of 1.020 or less), often by feeding canned food or adding water.^3,5
• The right diet: your vet will choose a diet based on the stone type.³ See urinary tract dog food.
• Treat infections promptly, especially in dogs that have had struvite stones.³
• Avoid supplements: in dogs that have had oxalate stones, avoid vitamin C and calcium supplements unless your vet advises them.⁵
• Regular rechecks: urine tests every few months and X-rays or ultrasound every 3 to 12 months, so new stones are caught while they're small enough to remove without surgery.^2,6,9

Frequently Asked Questions

What causes bladder stones in dogs?

Struvite stones usually follow a bladder infection. Oxalate, urate and cystine stones are linked to genetics, breed, diet and urine chemistry. Concentrated urine raises the risk of all types.

Can bladder stones in dogs dissolve on their own?

No, but struvite stones often dissolve on a prescription diet, usually within weeks. Calcium oxalate stones can't be dissolved and must be removed.

Are bladder stones an emergency?

They become an emergency if a stone blocks the urethra. A dog straining with little or no urine needs a vet right away, especially a male.

Do bladder stones always need surgery?

No. Struvite stones can often be dissolved, and many small stones can be flushed out or removed with scopes or lasers. Open surgery is still common for large or numerous stones.

Which dog breeds get bladder stones?

Miniature Schnauzers, Shih Tzus, Bichon Frises, Yorkshire Terriers and Lhasa Apsos are prone to oxalate stones; Dalmatians to urate stones; and Dachshunds and English Bulldogs to cystine stones.

Do bladder stones come back?

Often. Half of dogs with oxalate stones formed new ones within 2 years in one study. More water, the right diet and regular rechecks help.

Are struvite crystals the same as bladder stones?

No. Crystals are microscopic, can form in a sample after it's collected, and don't always mean stones are present. Stones can also occur without crystals.

What should a dog with bladder stones eat?

A diet chosen by your vet for the stone type, usually a prescription urinary diet, often in canned form to increase water intake.