New publications
Bladder and urethral stones in dogs
Last reviewed: 08.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Kidney stones are rare in dogs. But bladder stones are common. These stones can pass into the urethra. Bladder stones can form in all dogs. Breeds that are at high risk include the Miniature Schnauzer, Dalmatian, Shih Tzu, Dachshund, and Bulldog.
Bladder and urethral stones can be large or small, single or multiple, and may pass spontaneously or block the lower urinary tract. Bladder stones can also cause painful urination and blood in the urine.
Most bladder stones are struvites, which means they are made up of magnesium phosphate and ammonia. They form in alkaline urine, and are usually preceded by a bladder infection. Bacteria and urinary sediment form a nidus around which ammonium phosphate is deposited.
Uric acid stones form in acidic urine and are often associated with a genetic disorder of urate metabolism. Dalmatians and bulldogs have this genetic predisposition.
Other stones may contain calcium oxalate or cystine. Cystine crystals have been found in Newfoundlands and many other breeds of dogs. Genetic tests are available to determine predisposition or carriers of stones. Silica stones are rare and most common in male German Shepherds. These stones are not usually associated with a previous bladder infection.
Large or multiple stones can sometimes be felt through the abdomen. In most cases, the diagnosis is made based on the results of an X-ray examination. Stones that are not visible on an abdominal X-ray can often be seen with an ultrasound examination or intravenous pyelography. Urine tests are also taken into account.
Stones that have passed spontaneously or have been removed surgically should be analyzed if possible, since the composition of the stones affects the treatment of remaining or future stones.
Treatment: If there is an infection in the bladder, it should be treated as described for cystitis. In many cases, the stones can be resolved within a few weeks or months if the dog is fed a special diet. Struvite stones respond to acidic urine, which requires a low-magnesium, low-protein diet combined with a specially formulated food such as Royal Canin Urinary SO 13. Uric acid stones respond to a low-purine diet combined with the drug allopurinol. Cystine stones are treated with the same diet combined with cystine-dissolving drugs. Feeding your dog a vegetarian diet such as Royal Canin Vegetarian Formula may help prevent urate stones from forming. There is currently no known method to dissolve calcium oxalate and silicon stones. However, diet and supplements can help reduce the risk of their recurrence.
For stones in the urethra that may cause blockage and for bladder stones that do not respond to dietary changes and medications, surgical removal is the treatment of choice. It may also be used when medication is contraindicated due to congestive heart failure or when rapid symptom relief is needed.
New stones form in about 30% of cases. Your dog should be examined regularly by your veterinarian. He or she may recommend long-term dietary changes and/or supplements such as vitamin C, raspberry seed extract, or cranberry extract.
[ 1 ]