What Are the Causes of Oxalate Stones in Dogs?

Oxalate stones, or calcium oxalate stones, are essentially canine bladder or kidney stones much like the stones found in humans. These stones can require surgery to remove or crush so the dog can pass them naturally. They can be painful and cause painful urination or blood in the urine.

  1. What are Oxalate Stones?

    • Oxalate stones are composed of mineral salts that were not correctly broken down through the urine. Dog urine is naturally acidic, so when it becomes alkaline, the body is more prone to producing calcium oxalate stones. Some dogs do not correctly produce nephrocalcin, a natural substance that prevents the formation of the stones, which can lead to genetic predisposition to the ailment.

    Causes of Oxalate Stones

    • Oxalate stones can be caused by the body's inability to break down mineral salts, as well as from diets that are high in oxalate-producing foods. These foods include beets, sweet potatoes, green beans, okra, tomatoes, soy, wheat germ, nuts, sesame seeds, berries, grapes, lemon, lime and tangerines. This is not a complete list of all high oxalate-producing foods, so check with a vet to verify that a diet is not the cause of the stones.

    What dogs get Oxalate stones?

    • Some small dog breeds are predisposed to calcium oxalate stones, such as miniature schnauzers, Lhasa apsos, Yorkshire terriers, miniature poodles, shih tzus, and bichon frises. Approximately 75 percent of dogs that experience these stones are male. Stones typically manifest in dogs between 5 and 12 years of age.

    Treatment

    • The only sure way to remove the stones is through surgical removal. A vet can go into the bladder or urinary tract to remove the stones. Some vets opt the crush the stones and allow the dog to pass them on their own. The danger of leaving the stones untreated is when they travel through the urinary tract and can potentially block the urethra. A vet may also prescribe an oral dose of potassium citrate which causes the calcium in the urine to bond to the citrate instead of forming stones. Prevention of future stones can be managed by diet in some dogs.