What are bladder stones?
Bladder stones form from crystals in the urine of dogs. There are 4 types of bladder stones- calcium oxalate, struvite, cystine and urate. Crystals form from the mineral salts that are excreted by the kidneys into the urine. This is a natural function of the kidneys, but over time in some dogs, the crystals attach to each other and form stones. This is not an instant process so owners are rarely aware of bladder stones until their dog begins showing symptoms.
What are the symptoms of bladder stones?
Some dogs show no symptoms but blood in the urine is the most common symptom owners experience with their dogs. Many will urinate frequent, small amounts of urine. Male dogs may have interrupted streams of urine or have difficulty urinating at all. This is an emergency situation that requires immediate veterinary care. Some female dogs will actually pass stones from their vagina when urinating.
What causes bladder stones?
It is commonly believed that the type of food your dog eats can cause bladder stones. In fact, this is not true. We use diet to manage the condition, but the cause is dependent on the type of stones.
Cystine stones for instance result from an inherited defect in “bully breeds” due to excess secretion of the amino acid cystine into the urine.
Dalmatians have an inherited defect in amino acid metabolism that causes urate stones to form in the bladder.
Dogs with liver shunts are also prone to urate stone production in their bladders.
The most common stone types are calcium oxalate and struvite stones. 60% of cases of calcium oxalate are found in the Bichon Frise, Lhasa Opso, Miniature Schnauzer, Miniature Poodle, Shih Tzu and Yorkshire Terrier breeds.
This suggests some inherited disorder that promotes calcium oxalate crystal and stone formation in the bladder.
Struvite stones, the most common bladder stone in dogs, has a bit more complicated cause.
Dogs of any breed, with a history of bladder infections, can develop struvite crystals and stones. The changes in the bladder pH (alkalinity) from the infections promote the formation of struvite crystals and stones. Oddly, the breeds prone to oxalate crystal, are also prone to “sterile struvite” crystals and stones. This type of stone is not associated with infections and is some inherited disorder that promotes the condition.
How are bladder stones diagnosed?
An analysis of the urine can detect infection and crystals in the urine. An x-ray of the bladder is needed to confirm stones in the bladder.
How are bladder stones treated?
Treatment of bladder stones varies with the type of stone. But all stones can be managed with a combination of diet and medical treatment. The key take-home is that diet alone is not the answer.
Urine should be analyzed every 3 months after the diagnosis of crystals or stones and then annually or semi-annually, depending on the stone type, after the initial year. Most veterinarians recommend specially formulated commercial veterinary diets to manage bladder crystals and stones. Most owners object to these diets due to the high quantity of carbohydrates and feel they contain inferior ingredients.
We agree with that assessment. We also strongly recommend distilled water for stone-forming dogs because water quality and mineral content varies dramatically from water providers.
Calcium oxalate stones cannot be dissolved and need surgical removal before management strategies are started. A balanced homemade diet that is virtually oxalate-free can guarantee no further development of these crystals and stones. Treats for dogs with a history of oxalate stones should be meat only. All other treats, even dental treats, can contain oxalates.
Infection struvite stones do not need a special diet. Management of these stones requires veterinary treatment and prevention of the infection.
Sterile struvite stones do require a special diet. It must be a balanced low protein diet using meats that are low in phosphorus and magnesium.
Cystine and urate stones require a special low protein balanced diet that uses dairy, beans, or very limited choices of animal meats for protein.
But diet is only a first step! Constant urine monitoring and supplements and medications may also be needed to control urine crystals and stones.
At The Well Dog Place we have had great success with Chinese herb formulas and essential oils to aid our diets for crystal and stone control.