Bladder Stones in Cats


It is a common belief among researchers that bladder stones are caused by high levels of the minerals magnesium, phosphate and ammonium in your cat’s urine. The excessive mineral levels produce crystals in cat urine which eventually form stones. The size of the stones can vary from as small as a spec of sand to as big as a small pebble. The most common types of stones are struvite and calcium oxalate. When these stones form, they can block one of the tubes leading from your cat’s kidney to its bladder, making urination painful and difficult.


Felines of all ages can experience bladder stones; although the risk of stones forming does tend to increase with age. Some breeds, such as the Persian, Himalayan and Burmese felines also seem to be more predisposed to getting bladder stones. The following factors are also believed to increase the chance of bladder stones forming:

  • Insufficient intake of water
  • Recurring urinary tract infections
  • Abnormal PH level in urine
  • Some dietary supplements and drugs
  • Poorly balanced diet

It is also believed that a diet of exclusively dry food helps make your cat more prone to bladder stones than a diet of moist, high quality canned food. The reasoning behind this theory is that cats who eat mostly dry food are usually dehydrated to some degree. If you feed your cat a dry food diet, it is imperative to make sure you provide plenty of clean, fresh water every day and that you encourage him to drink.
Diabetes and hyperthyroidism are two conditions that increase the risk of feline urinary tract infections, which may result in bladder stones forming.


Although some cats may not exhibit all the signs or any signs at all, the following are some of the common signs of bladder stones:

  • Painful urination
  • Frequent urination
  • Excessive licking of genital area
  • Spraying urine
  • Urinating in places other than the litter box
  • Frequent or recurring urinary tract infections
  • Blood in urine
  • Difficulty urinating

For larger stones which are already causing a blockage:

  • Nausea
  • Vomiting
  • Distended abdomen (visually larger than usual and firm to the touch)
  • Loss of appetite

If these symptoms appear, the condition is an emergency and may be life-threatening if treatment is not sought immediately.


Your veterinarian may use several methods to properly diagnose bladder stones. Larger stones may be felt by external palpitation and examination of your cat’s abdomen; although the stones would have to be very large at that point. If the stones are not big enough to be felt externally, radiographs (x-rays) or ultrasound may be needed to confirm diagnosis. If bladder stones are suspected, your veterinarian may also use urinalysis or a urine culture.
Once diagnosis of bladder stones has been confirmed, your veterinarian will choose an effective treatment. If the stone is large, surgical removal may be necessary. If the stone is too small to appear on an x-ray, a simpler treatment such as increasing your cat’s water intake may be sufficient enough to help your cat’s body pass the stone naturally during urination. A female cat’s urinary tract is not as narrow as a male’s, so passing the stones is easier for their bodies to achieve. Your veterinarian may also choose a procedure called “lithotripsy” (using shockwaves to break up the stone so that the smaller pieces can be passed naturally during urination).
Another treatment used to help treat bladder stones is to try and flush them out of your cat’s body by filling the bladder and inducing urination.


After being treated for a bladder stone, your veterinarian will be able to tell you which type of stone your cat experienced and what you can do to help reduce the risk of future recurrences. Some possible preventative measures may include:

  1. Dietary change from dry food to canned food
  2. Increasing your cat’s water intake (which would require close monitoring of how much water your cat drinks daily and encouraging him to drink more)
  3. Regularly scheduled urinalysis (throughout the year for felines who are more susceptible)
  4. Increased exercise to help keep your cat’s system healthy and active

Did your cat have have bladder stones? How did your veterinarian treat the condition? Let us know in the comments!

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