Calcium Deposits in the Urinary Tract in Cats

Though calcium deposits are rare in cats, they are more likely to happen in cats that are older. Keeping the cat well hydrated and providing the proper types of food is essential in preventing calcium deposits from occurring.

Urolithiasis is a condition in which rock-like stones, which are typically made of either calcium or struvite, form in the urinary tract. Stones made primarily of calcium oxalate are known as calcium deposits. The stones can range in size from extremely small to several millimeters in diameter. When the stones rub against the cat's bladder walls, inflammation can occur. With the proper treatment, most cats make a complete recovery.

The severity of symptoms depends on the size of the calcium deposits and how much inflammation in the bladder has occurred from their presence.

• Painful urination
• Straining during urination
• Blood in the urine
• Enlarged abdomen due to inflammation in the bladder
• Frequent urination
• Red or irritated genitals
• Frequent licking of the genitals
• Urine spraying
• Chronic urinary tract infections
• Urinating in unusual places

Calcium deposits are primarily caused by high levels of calcium in the urine. Excessive calcium levels may be caused by the following:

• Excessive amounts of protein in the diet
• Decreased water intake or dehydration
• Vitamin B6 insufficiency
• Eating a diet that consists primarily of dry food
• History of urinary tract infections
• Use of steroids
• Use of calcium supplements
• Congenital liver shunt
• Excessive levels of magnesium, phosphate and ammonium minerals in the urine
• Being a breed that is more predisposed to calcium deposits, such as Burmese, Ragdoll, Himalayan, Scottish Fold or Persian

The veterinarian will ask for the cat's healthy history, which includes when the symptoms began, any history the cat has of urinary tract infections and the cat's eating and drinking habits. The veterinarian will then gently examine the cat. Large calcium deposits can sometimes be felt through the cat's abdominal wall. The veterinarian will feel for these deposits and examine the cat's genitals for signs of irritation.

Blood work, a urine culture, and a urinalysis will be done to rule out other conditions that may be causing the symptoms, such as kidney damage or a urinary tract infection. The labs can also help the veterinarian determine a cause for the calcium deposits, such as high levels of other minerals in the urine.

Ultrasounds and x-rays may also be taken of the cat's bladder, abdomen and kidneys to provide a definitive diagnosis of the calcium deposits and what is causing them to form. These tests are especially helpful in identifying stones that are too small to be felt through the cat's abdominal wall.

Bladder Flushing

This treatment is preferable for stones that are small in size. A catheter will be inserted into the cat's bladder, which will then be flushed with fluids to remove the stones and any residual sediment from the bladder walls. The veterinarian may also massage the cat's abdomen and bladder during the procedure to encourage the stones to flow out.

Surgical Removal

If the calcium deposits have grown large and are blocking the flow of urine, surgery will need to be performed in order to prevent the blockage from causing kidney damage. The cat will be given general anesthesia during the procedure. Next, the cat's abdomen will be shaved to remove hair from the incision site. The veterinarian will then make a small cut in the skin and remove the bladder. A small incision in the bladder will allow the veterinarian the space necessary to remove the stones, which will be sent to a lab for further analysis. Dissolving sutures will then be used to close the bladder before it is put back into place. The cat's abdomen will then be sutured.

Lithotripsy

Lithotripsy is a procedure that uses shock waves to break up large calcium deposits into small pieces, which can then leave the urinary tract with the urine. Lithotripsy is commonly used on large stones that are irritating the bladder walls but aren't blocking the flow of urine. The procedure is non-invasive and is done in-office.

If the cat had the stones surgically removed, he or she will need to stay in the hospital for several days in order to monitor their condition and the healing of the incision. The veterinarian will also want to monitor the cat in-office to ensure that any small stones that were broken up via lithotripsy have left the bladder and urinary tract.

Calcium deposits are likely to recur without changes to the diet. It is recommended that cats eat a diet low in magnesium, phosphate, ammonium, and calcium to prevent the stones from recurring. Cat's should be given fresh water daily, as many cats will refuse to drink water that is stale or has debris in it, such as hair.