Uroliths in Pets: Causes, Signs & Management Guide

“Uroliths” is the medical term given to large collections of crystals that mineralise and form anywhere in the urinary tract. They can include kidney stones and bladder stones, as well as smaller stones lodged in the ureters or urethra.

Most crystals in urine are dissolved and cause no major problems in small amounts. However, uroliths form when microscopic crystals precipitate out of solution and group together into solid, concrete-like stones. Common types include magnesium ammonium phosphate hexahydrate (struvite), calcium oxalate, urate, cysteine and silicate. Large uroliths may comprise layers of different crystal types.

Who gets urolithiasis? Understanding breed predispositions and risk factors

Urolithiasis is the presence of stones in the urinary tract. While any animal, including humans, can develop urolithiasis, some pets are more prone based on breed, underlying conditions, and infections.

• Struvite stones often form due to urine infections which alter the urine pH. Females are more susceptible due to higher risk of infections. Breeds predisposed to struvite uroliths include Miniature Schnauzers, Miniature Poodles, and Bichon Frise.
• Calcium oxalate stones are very common in cats (about 60% of feline urinary stones) and dogs (around 35%). Miniature Schnauzers, Miniature Poodles, Yorkshire Terriers (link) and Shih Tzus (link) show higher incidence.
• Urate stones occur frequently in Dalmatians (link) due to a genetic liver metabolism defect. Pets with liver shunts can also develop these.
• Cysteine stones are rarer but often seen in young male Dachshunds (link).
• Silicate stones tend to form in large breeds, including German Shepherds (link) and Labradors (link). These have been linked to diets rich in corn gluten and soybeans.

Recognising the signs of urolithiasis in pets

Pets affected by urolithiasis may:

• Struggle or show pain when passing urine
• Have frequent urges to urinate with little output
• Pass blood in their urine
• Completely stop passing urine, which is an emergency

If your pet shows any of these symptoms, particularly if they cannot urinate, you should seek veterinary care immediately.

How do vets diagnose urolithiasis?

Bringing a fresh urine sample to your vet is highly useful, reducing delays in diagnosis. Vets perform thorough clinical exams including, for male dogs, prostate checks. Diagnostic tools include:

• Urine analysis and dipstick tests
• Blood tests to assess kidney function and infection
• Imaging such as X-rays and ultrasound; ultrasound is preferred for detecting stones in many cases according to the latest UK & European Urolithiasis guidelines (2025)

For animals with urinary obstruction, relieving the blockage with sedation and catheterisation is urgent to prevent kidney damage before extensive diagnostics.

Treatment options based on stone type and size

Treatment depends heavily on stone composition, size, and location. While laboratory analysis of stones is definitive, vets use clinical clues like breed, urine pH and imaging to guide initial management.

• Small stones such as certain struvite types can be medically dissolved with diet aimed at altering urine pH to dissolve crystals.
• Specialist centres now offer minimally invasive options like laser lithotripsy during catheter procedures, which break stones for easier passage, though availability is limited.
• Larger stones often need surgical removal via cystotomy to scoop stones out. Post-op care involves hospitalisation for fluid therapy, pain management, and frequent toileting to avoid complications.

Will uroliths return? Prevention and long-term care

Recurrence depends on underlying cause:

• Struvite stones secondary to infections can often be prevented permanently by treating those infections.
• Genetic predispositions, common in breeds like Dalmatians, increase chances of repeated stones. Long-term dietary management and regular vet follow-up are key.

Veterinarians emphasise that urolithiasis is a chronic condition requiring ongoing monitoring, diet adjustments, and prompt attention to urinary symptoms to prevent serious complications.

Responsible pet ownership and final thoughts

Though uroliths are relatively uncommon, any pet showing signs of urinary discomfort or cystitis should have their urine checked to exclude stones or crystals early. Prompt veterinary consultation can improve outcomes significantly.

Owners with predisposed breeds should work closely with their vets on dietary strategies and preventive care. Avoiding untreated infections and providing fresh water at all times help maintain urinary tract health.

By understanding uroliths and acting early, you can help your beloved pet enjoy a healthier, happier life.