Bladder stones — uroliths — form when minerals in urine crystallise and aggregate. They cause irritation, bleeding and pain, and in male dogs they can block the urethra, which is life-threatening.
The key point is that different stone types need different, sometimes opposite, management. Guessing is not an option.
The emergency
A dog straining to urinate and producing nothing is an emergency, particularly a male.
The urethra narrows as it passes over the pelvis, and a stone lodging there blocks urine flow completely. The bladder distends, pressure backs up to the kidneys, toxins accumulate, and electrolyte disturbances affect the heart. Without treatment this is fatal within roughly 24 to 48 hours.
Signs of blockage: repeated attempts to urinate with little or nothing produced, crying, restlessness, a tense painful abdomen, vomiting, lethargy, collapse.
Go immediately. Do not wait to see if it resolves.
The usual signs
Short of blockage:
- Frequent urination, in small amounts
- Straining
- Blood in the urine
- Urinating in unusual places, or accidents in a house-trained dog
- Licking at the genitals
- Discomfort
- A strong smell to the urine
- Sometimes nothing at all — stones are often found incidentally
These overlap almost exactly with a urinary tract infection, which is why testing rather than assuming matters.
The main types
Struvite (magnesium ammonium phosphate). Most commonly associated with urinary tract infection — certain bacteria produce urease, raising urine pH and precipitating struvite. More common in female dogs.
These can often be dissolved with diet, plus treating the infection, avoiding surgery entirely. That is a substantial advantage.
Calcium oxalate. More common in male dogs and in certain breeds — Miniature Schnauzers, Bichons, Lhasa Apsos, Yorkshire Terriers, Shih Tzus.
These cannot be dissolved. They must be removed, and then prevented.
Urate. Associated with liver disease including portosystemic shunts, and genetically with Dalmatians, who have a breed-wide difference in uric acid metabolism. Sometimes dissolvable.
Cystine. Related to an inherited defect in kidney transport. Seen in Newfoundlands, Dachshunds and Bulldogs among others.
Silicate and mixed stones. Less common.
Diagnosis
- Urinalysis, including pH, sediment examination for crystals, and culture for infection
- Imaging. X-rays show most stones; ultrasound shows those that are radiolucent, including some urate and cystine stones
- Stone analysis after removal. This is the step that determines everything afterwards, and it should always be done
Crystals in urine are not the same as stones. Many healthy dogs have some crystals, particularly in a sample that has been sitting. Crystals alone do not diagnose stone disease.
Treatment
Dissolution, where the stone type allows. A therapeutic dissolution diet, plus antibiotics for infection, over weeks to months with imaging to track progress. Works well for struvite.
Surgical removal (cystotomy) for stones that cannot be dissolved or where there is obstruction.
Non-surgical removal options include urohydropropulsion — flushing small stones out under anaesthetic — and laser lithotripsy at referral centres.
Emergency management of a blockage: catheterisation to relieve pressure, fluids, correction of electrolytes, then definitive treatment.
Prevention: the part that matters
Recurrence rates are significant, so prevention is the long game.
1. Dilute the urine. The single most effective measure across all stone types.
- Feed wet food, which substantially increases water intake
- Add water to food
- Water in multiple bowls, everywhere
- Encourage drinking — some dogs drink more from a fountain
- The aim is dilute, pale urine
2. Feed the right therapeutic diet, based on stone analysis. This is where getting the type identified pays off — a diet that prevents struvite can encourage oxalate, and vice versa.
3. More frequent opportunities to urinate. Urine held for long periods is more concentrated and gives crystals more time to aggregate.
4. Treat infections promptly, particularly for struvite formers.
5. Do not add supplements or treats without asking. Many affect urine pH or mineral load. Vitamin C supplementation, for instance, can increase oxalate.
6. Monitor. Periodic urinalysis and imaging at the interval your vet sets.
Some links on this page are affiliate links. If you buy through them we may earn a small commission at no extra cost to you — it helps keep this site free. We only recommend products we would use with our own dogs.
XIAZ Elevated Dog Bowl Stand
Multiple accessible water stations are the practical side of urine dilution — and for older or arthritic dogs, a comfortable height makes them drink more readily. Check the height suits your dog, and note that raised feeders are not recommended for deep-chested breeds.
PupFlask Dog Water Bottle
So water intake continues on walks and in the car rather than only at home. For a stone-forming dog, every extra drink is preventive treatment.
Breed and sex notes
Miniature Schnauzers, Bichons, Shih Tzus, Lhasa Apsos, Yorkshire Terriers — higher oxalate risk.
Dalmatians — urate, because of the breed-wide difference in purine metabolism. Diet is central, and this is well understood in the breed.
Male dogs — much higher risk of obstruction because of urethral anatomy. Any male dog straining to urinate is an emergency until proven otherwise.
Female dogs — higher rate of struvite, linked to a higher rate of urinary infection.
The one-line version
If your dog has had a stone, the two things that matter are: what type was it, and is the urine dilute enough.
Get the analysis, feed the matching therapeutic diet, and make water the easiest thing in the house to find.
