What are Urinary Stones?

Urinary stones (bladder stones and kidney stones) are also known as uroliths. Kidney stones are rare in cats, however bladder stones are a common urinary disease. This is composed of minerals, crystals and organic materials. These stones can develop anywhere in the cat’s urinary system. Bladder stones can rub against the wall of the bladder, causing inflammation of the bladder. There are various sizes of stones in the kidney and bladder such as sand-like, small, and large stones. The most common type of bladder stones are struvite and calcium oxalate stone.

The Symptoms of Urinary Stones

・Bloody urine
・Urinating or attempting urinate, more frequent than normal)
・Straining to pass urine, crying out and being vocal
・Over Grooming around the urinary opening and lower abdomen
Complete urinary obstruction resulting in the inability to pass urine - It is important to seek an emergency veterinary clinic. If this is not treated soon, urine obstruction can be a life-threatening complication.

If you have any of the above symptoms, your cat may feel uncomfortable or in pain, so we recommend that you visit a vet clinic as soon as possible.

Causes of urinary stones

・Poor diet
・Inflammation or infection
・possibly the pH level of the cat’s urine
・genetic factor

Struvite stones (triple phosphate)

In most cases, cats develop struvite stones in the absence of an infection. The considering factors of struvite stones are such as increased urine pH (alkaline urine), and increased magnesium and phosphorus in the urine. Siamese cats are also a risk factor of struvite stones.

Oxalate stones (calcium oxalate)

The exact cause of oxalate stones is unknown. However, the risk factor has been researched. For instance, certain purebred cats ( Burmese, himalayans, Persians, and Siamese), obese, and middle age cats. Also, the lower pH urine (acid urine) can contribute to oxalate stones, which increase in recent years. Because pet food company began to make more acid foods for preventing struvite stones, so that the number of oxalate stones in cats have increased.

Bladder Stones Treatment

Your cat’s treatment depends on the type of stone and where it is formed. The most effective approach to treat bladder stones in a cat is two options:


Cystotomy is surgery to open the bladder and remove stones. This is the fastest and the most common option for cats to treat bladder stones. Especially the cats having complete obstruction need immediate surgery. If your cat’s obstruction can be removed by passing a catheter, your cat may not need surgery. Occasionally, a vet may recommend to wait until passing the stones naturally.

A special diet

A special diet is for dissolving the stones by changing the pH. This can avoid surgery, however, it does not work well for all stones, takes longer time, and is possible not to have this diet for your cat.

Toletta is a very useful litter box to find out the symptoms of urinary stones. In order to prevent urinary stones, you can notice the slight change of your cat every day by monitoring urine volume, count, behavior in Toletta.