Skip to main content
A beautiful, yellow-eyed cat receiving treatment. Doug Hall feeding a well-loved client.

Shilo's bladder stone

15th November 2010
Shilo, an 8yr old Siamese cat, developed a problem urinating while his owners were abroad . The cattery noticed that he was not using his tray and had gone off his food. He was transferred to The Cape on the 8th September; he had been put on a drip and had a urinary catheter placed by the emergency vets used by the cattery.

He was very weak and ill on arrival. Our nurses, Laura and Jackie settled him in while we waited for blood results to be sent through, so we could plan his further diagnostic work-up and treatment. They put him onto an infusion pump which delivers fluid intravenously, measuring the flow rate to safely deliver the correct amount needed by the patient. We attached the urinary catheter to a collection bag, to prevent infection travelling up the catheter into the bladder. This way we can also monitor how much urine is being produced and its appearance.

His blood results revealed that he was dehydrated and had very high renal enzyme levels- this told us that the kidneys had been damaged by him not passing urine.

An ultrasound examination of the bladder showed a thickened bladder, containing a single, large stone. We took a urine sample by cystocentesis( guiding a needle into the bladder using the ultrasound picture).Testing the urine, by centrifuging a sample to look at the sediment and measuring specific gravity, pH and other parameters, revealed a bloody, acid urine with signs of infection in the bladder.

The following day, the blood tests, which we run in-house, showed a great improvement in the renal enzyme levels and we felt it was safe to go ahead with surgery to remove the stone.

Under general anaesthetic, the bladder was opened up and the offending stone removed- it was about 1.5mm in diameter- which may not sound big, but would block the narrow urethra, as it had already done, when the bladder tried to expel it. The bladder was very bruised and thickened from being prevented from normal filling and emptying, even after only a few days.

Keeping our patients warm and carefully monitored during and after their surgery is very important and our dedicated nurses made sure that Shilo had a good, quick recovery from his long surgery.

He was kept in hospital for another 6 days and nights, where he was monitored for urine production once his catheter was removed and treated for pain and against the infection in the bladder. He needed syringe and then hand-feeding every few hours ( and a lot of fussing and cuddling- he is a Siamese after all!)

The stone was sent to an external laboratory for analysis, the result of which was that it was a Calcium Oxalate urolith (bladder stone). Knowing this we could devise a plan to prevent more stones developing by changing his diet to one that produces an alkaline urine.

It took several weeks before Shilo was eating and urinating normally and required frequent check-ups where, by measuring his weight, checking his urine, doing follow-up blood test to monitor his renal function we were able to assess his needs and support him during his recovery. Thanks to the commitment of his wonderful owners, he has made a full recovery and at last check shows no signs of developing any more urine crystals or stones.

What are bladder crystals and stones?

Cats can develop three types of urine crystals: struvite, oxalate or urate. Any of of which can with time and in the right conditions, form into bladder stones. An owner may be unaware of stones forming until it becomes a life-threatening situation, as in Shilo’s case.

Stuvite crystals form in alkaline urine, while oxalate and urate crystals form in acidic urine. Urine acidity is affected by diet and bacterial activity, as bacterial metabolites change the pH.

An excess of any of the salts which form crystals( ammonia, phosphate, magnesium) as well as certain vitamins or medications, or insufficient water intake, will also encourage crystal growth. At this stage they can be passed in the urine without too much trouble, but once they aggregate and become bigger, they cause discomfort and usually some bleeding while being passed down the urethra. Males struggle more, as their urethras are longer and narrower. Once stones of larger dimension are formed, surgical removal may become the only option.

As a cat owner it is vital to pick up on small changes in behaviour-
*frequent visits to litter tray or outdoors with little passed
*moaning/crying when urinating
*urinating in unusual places: floors, baths etc
*increased grooming around the urethral opening

This is the time to see the vet- urine can be checked for presence of bacteria, which can be treated before they change the urine pH, or for presence of crystals, which can be dissolved by changing diet or giving specific medications. Ultrasound can be done to examine the bladder for changes and presence of sediment and/or stones. Once stones of larger dimension are found, surgery may become the only option.

Crystals and stones can be prevented by ensuring your cat takes in enough water. This may require having water bowls in several areas indoors and outdoors, for easy access, or getting a drinking fountain, for cats who prefer drinking running, fresh water. A well-balanced diet, appropriate for the cat’s age and status are essential. Do not give tit-bits or unprescribed supplements. Have regular health checks, including urine tests if any abnormal urination behaviour is noted.