Struvite stones in cats

Bladder stones may cause painful urination, frequent urination in small amounts, straining to urinate, indoor urination, blood in the urine or even an inability to urinate. The resulting buildup of waste in the blood may make your cat feel ill, changing its behavior. Learn what you can do about bladder stones here.

What is struvite?

“Bladder stone” refers to various types of stones and/or crystals found in the urine of dogs and cats. These stones are categorized based on the mineral composition of the stone or crystal. Struvite is one of the most common types of bladder stone and consists of magnesium, phosphate and ammonium. If the urine is more basic (high pH), this poses a greater risk of struvite stone formation. Basic urine (high pH) may be caused by diet or by a urinary tract infection. Bladder stones may cause painful urination, frequent urination in small amounts, straining to urinate, indoor urination, blood in the urine or even an inability to urinate. The resulting buildup of waste in the blood may make your cat feel ill, changing its behavior.

Once a cat has had bladder stones, it is generally more susceptible to developing them again in the future. That is why it’s important to take measures to dissolve struvite stones and to prevent new ones from forming.

What can you do?

  • Anti-Struvite Diet

Unlike other types of bladder stones, struvite stones dissolve in acidic urine (low pH). An effective anti-struvite diet must contain low levels of struvite-forming components (magnesium, phosphorous and protein), and it must also reduce the pH of the urine to between 6.0 and 6.4. This dissolves the existing struvite stones and prevents new ones from forming. On average, your cat’s struvite stones will dissolve after 2 to 6 weeks on an anti-struvite diet. But this time frame may vary widely from one cat to another.

  • No extras

For the best results, it is vital to avoid giving your cat any foods or drinks besides the anti-struvite diet. Snacks, food for other cats (or other pets), table scraps or prey from outdoors can affect the composition and pH level of the urine and result in the formation of new struvite stones.

  • Encourage drinking

Cats naturally drink sparingly, resulting in concentrated urine. Drinking a lot of fluids will dilute the urine, reducing the risk of struvite stones. You can promote fluid intake by regularly setting out fresh water and also by providing a cat drinking fountain, if necessary.

  • Multiple clean litter boxes

Ensure that the cat is not holding its urine up by providing plenty of clean litter boxes in your home. We recommend having one litter box for each cat in the home, plus one additional litter box.

  • Measure the pH of the urine regularly

We recommend measuring the pH of the urine regularly (once every 2 to 4 weeks). Urine acidity fluctuates over the course of the day. This is due to factors such as meal times. Urine is more acidic (lower pH) before a meal than afterwards. For this reason, it is important to always measure the acidity of the urine at the same time of day (or at multiple times) and after a meal. If the pH level is greater than 6.5, arrange for your veterinarian to check your cat’s urine for bladder stones and possibly also for bacterial infection.

  • Multiple small meals

To minimize fluctuations in urine pH levels, it is best to give your cat multiple small meals every day. This means it is best to provide continual access to food, unless this results in overeating.