Health & Diseases

Urinary Stones in Dogs: Types, Symptoms & Treatment

Urinary stones (uroliths, urolithiasis) are mineral concretions that form in the urinary tract of dogs—kidneys, ureters, bladder, or urethra. They occur when certain minerals in the bile become supersaturated and crystallize. The most common stone types in dogs are struvite (magnesium ammonium phosphate), calcium oxalate, urate, and cystine.

Urinary stones in dogs: types, symptoms & treatment

What are urinary stones in dogs?

Urinary stones (uroliths, urolithiasis) are mineral concretions that form in a dog’s urinary tract — kidneys, ureters, bladder, or urethra. They develop when certain minerals are supersaturated in the urine and crystallize. The most common stone types in dogs are struvite (magnesium ammonium phosphate), calcium oxalate, urate, and cystine.

Urinary stones become clinically relevant when they cause urinary flow problems, irritation of the mucous membranes, or infections. Urethral obstruction in a male dog is a medical emergency.

Background + scientific classification

Lulich et al. (2016, Journal of Veterinary Internal Medicine, PubMed 27507098) published the ACVIM consensus recommendations for the treatment and prevention of urinary stones: the treatment strategy depends on the type of stone — struvite stones can be dissolved non-surgically with a dissolution diet (phosphate- and magnesium-restricted therapeutic food + urine acidification). Calcium oxalate stones cannot be dissolved through diet — surgical or endoscopic removal is required. Genetic predisposition plays a key role in urate and cystine stones.

Bartges and Callens (2015, Veterinary Clinics of North America, PubMed 25732712) described the pathophysiology and diagnostics: stone formation is multifactorial — diet, hydration, urine pH, infections, and genetics interact. Ultrasound and X-rays are standard diagnostics; stone analysis (after removal) is essential for targeted treatment and prevention. Without stone analysis, dietary prevention is ineffective or counterproductive.

Houston et al. (2004, Canadian Veterinary Journal, PubMed 15108694) analyzed Canadian urolith submissions over several years: struvite stones in female dogs (often associated with infection) and calcium oxalate stones in middle-aged male dogs were predominant. Breed predispositions exist: Miniature Schnauzers, Bichon Frisés, and Lhasa Apsos for calcium oxalate; Dalmatians and English Bulldogs for urate stones.

Vitomalia position

Urinary stones are not a nutritional problem that can be solved with “more water” — they are a diagnostic task. Without stone analysis and stone type identification, prevention is guesswork. Anyone who does not clarify the underlying cause of recurrent urinary stones is investing in ineffective diets.

When do urinary stones become relevant in dogs?

  • If symptoms occur: bloody urine, pain when urinating, frequent urge to urinate without results
  • In male dogs with urinary obstruction: medical emergency, see a veterinarian immediately
  • In breeds with a known predisposition (Dalmatians, Miniature Schnauzers, English Bulldogs)
  • For recurrent bladder infections: rule out stones as the cause
  • After surgical stone removal: dietary recurrence prevention

Practical application

Common stone types in dogs — overview:

Stone type Frequency Predisposition Dissolvable through diet
Struvite ~50% Female dogs, infection Yes (+ antibiotics)
Calcium oxalate ~35% Male dogs, middle age No
Urate ~5% Dalmatian, Bulldog Partial
Cystine ~2% Genetic (Newfoundlands and others) No

management: 1. Diagnosis: ultrasound + X-ray for localization 2. Stone removal: dissolution diet (struvite), cystoscopy, urethrotomy, or cystotomy 3. Stone analysis: essential for prevention 4. Recurrence prevention: stone-specific diet, increased water intake, regular control

Common mistakes & myths

  • “More water helps against all urinary stones.” Increased water intake lowers the concentration of minerals and is useful for prevention — but it is not a treatment for existing stones.
  • “A kidney diet is enough for prevention.” Without stone analysis, the right diet is unknown. A struvite diet can promote calcium oxalate stones and vice versa.
  • “Urinary stones only occur in older dogs.” Stone formation can occur at any age. Genetic forms (urate in Dalmatians, cystine in Newfoundlands) often appear at a young age.

Scientific status 2026

Endoscopic stone removal (urethroscopy, cystoscopy) has expanded minimally invasive options. Laser lithotripsy for calcium oxalate stones is available in specialized clinics. Genetic testing for dogs with a predisposition (e.g., SLC2A9 mutation in Dalmatians for urate stones) enables targeted early prevention. Commercial dissolution diets for struvite are well standardized.

Frequently asked questions

How do I recognize urinary stones in dogs?

Common signs: bloody urine, difficult/painful urination, frequent passing of small amounts of urine, licking the genital area, restlessness. Urethral obstruction in male dogs (no urination despite a strong urge): an immediate emergency. Diagnosis by ultrasound and X-ray at the veterinarian.

Can I prevent urinary stones in dogs?

Prevention depends on the specific type of stone — which is why stone analysis is important after every stone event. Generally helpful: high water intake (wet food, water fountain), a stone-specific diet, regular urine checks in predisposed breeds. Without stone analysis, targeted prevention is not possible.

Do urinary stones always require surgery?

No. Struvite stones (infection-associated) can often be dissolved in dogs with a dissolution diet + antibiotics — without surgery. Calcium oxalate, cystine, and larger urate stones usually need to be removed endoscopically or surgically. Small stones can sometimes pass spontaneously.

Related terms

Sources & further reading

  1. Lulich, J. P., Berent, A. C., Adams, L. G., Westropp, J. L., Bartges, J. W., & Osborne, C. A. (2016). ACVIM Small Animal Consensus Recommendations on the Treatment and Prevention of Uroliths in Dogs and Cats. Journal of Veterinary Internal Medicine, 30(5), 1564–1574. https://pubmed.ncbi.nlm.nih.gov/27507098/

  2. Bartges, J. W., & Callens, A. J. (2015). Urolithiasis. Veterinary Clinics of North America: Small Animal Practice, 45(4), 747–768. https://pubmed.ncbi.nlm.nih.gov/25732712/

  3. Houston, D. M., Moore, A. E. P., Favrin, M. G., & Hoff, B. (2004). Canine urolithiasis: a look at over 16 000 urolith submissions to the Canadian Veterinary Urolith Centre from February 1998 to April 2003. Canadian Veterinary Journal, 45(3), 225–230. https://pubmed.ncbi.nlm.nih.gov/15108694/

Wissenschaftliche Einordnung

Lulich et al. (2016, Journal of Veterinary Internal Medicine, PubMed 27507098) published the ACVIM consensus recommendations for the treatment and prevention of uroliths: Treatment strategy depends on the type of stone — struvite stones can be dissolved non-surgically with a dissolution diet (low-phosphate and low-magnesium diet food + urine acidification). Calcium oxalate stones are not amenable to dietary dissolution — surgical or endoscopic removal is required. Genetic predisposition plays a key role in urate and cystine stones.

Bartges and Callens (2015, Veterinary Clinics of North America, PubMed 25732712) described pathophysiology and diagnostics: Stone formation is multifactorial — diet, hydration, urine pH, infections, and genetics interact. Ultrasound and X-ray are standard diagnostics; stone analysis (after removal) is essential for targeted therapy and prevention. Without stone analysis, dietary prevention is ineffective or counterproductive.

Houston et al. (2004, Canadian Veterinary Journal, PubMed 15108694) analyzed Canadian urolith submissions over several years: Struvite stones in female dogs (often infection-associated) and calcium oxalate stones in middle-aged male dogs predominate. Breed predispositions exist: Miniature Schnauzers, Bichon Frisé, Lhasa Apso for calcium oxalate; Dalmatians and English Bulldogs for urate stones.