Introduction
Bladder stones, medically referred to as uroliths or bladder calculi, are accumulations of minerals and other substances in the urinary bladder. Uroliths can occur in any part of a cat’s urinary tract, from the kidneys to the ureters to the urinary bladder and ultimately to the urethra, although the urinary bladder is the most common site of urolith formation. They can predispose affected animals to recurrent and painful urinary tract infections. Stones become especially problematic when they obstruct the normal outflow of urine – a condition that will rapidly become life-threatening without immediate treatment. Once a cat has been diagnosed with bladder stones, the treatment options will depend upon the size and number of uroliths in the bladder and the composition of those stones.
Treating Bladder Stones in Cats
Bladder stones can be treated either medically or surgically.
Bladder stones that are smaller than the smallest diameter of the affected cat’s urethra may be treatable with a non-surgical procedure called urohydropropulsion, or catheter-assisted retrograde urethral flushing. During this procedure the cat is sedated or anesthetized, a sterile urinary catheter is inserted through the urethra, a sterile isotonic nonirritating solution such as normal saline or lactated Ringer’s solution is flushed up through the catheter into the bladder, and then the bladder is manually expressed to (hopefully) flush out the stones. Abdominal radiographs normally are taken before and after this procedure to verify that all uroliths were successfully removed.
When a cat is suffering from inordinately large or numerous bladder stones, surgery normally is necessary. The surgical procedure is called a cystotomy. During a cystotomy, the cat will be placed under general anesthesia. The veterinary surgeon will make an incision through the abdominal wall and another into the urinary bladder, and then will physically remove the uroliths through these incisions. Afterwards, the veterinarian will flush the bladder thoroughly with sterile saline to ensure that the incisions are properly and completely closed. This surgical procedure is normally very successful and carries a low risk of post-operative complications.
Once bladder stones are removed, they will be sent to a laboratory for assessment of their particular composition. This information is essential to help the treating veterinarian develop an appropriate forward-thinking prevention plan. The recurrence of some types of stones can be prevented or at least reduced by placing a cat on a specialized diet, while other types of stones may recur due to an underlying condition that needs further medical management.