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Calcium Oxalate Bladder Stones in Dogs

Calcium oxalate stones are common in dogs.

Bladder stones are rock-like structures that form inside of a dog's bladder. They're made out of minerals, and calcium oxalate stones are one of the three main types seen in dogs.

Cause of Calcium Oxalate Stones in Dogs

Urine is full of waste products, dissolved in water and waiting to exit the body. When the pH level of the urine is not exactly right, some of the minerals don't dissolve in it and can gather together to form crystals or stones.

Calcium oxalate stones can occur if a dog's urine is too acidic and too concentrated.

Signs of Calcium Oxalate Stones in Dogs

The signs of calcium oxalate bladder stones in dogs are the same as the signs of any bladder stone and include:

  • Bloody urine
  • Frequently urinating small amounts
  • Straining to urinate
  • Urinary accidents in the house
  • Licking incessantly at the vulva or penis

Some dogs don't show any signs of bladder stones. Conversely, stones can become severe enough that they block the urethra, resulting in obstruction of the urine's exit from the body. This is a life-threatening situation that can cause the bladder to burst or kidney failure to develop. If your dog is straining to urinate but not producing any urine, it is an emergency situation; get him or her to the veterinarian as soon as possible.

Dog Breeds Most Commonly Affected by Calcium Oxalate Bladder Stones

Dogs that are affected by calcium oxalate bladder stones more often than other breeds include:

  • Bichons
  • Schnauzers
  • Yorkshire terriers
  • Lhasa apsos

Diagnosis of Canine Calcium Oxalate Bladder Stones

Bladder stones may be suspected by a veterinarian based on history and examination of a urinalysis. In rare cases, the doctor may be able to feel stones present in the bladder by palpating (feeling with the fingers) the dog's abdomen.

However, x-ray or ultrasound is needed to positively diagnose bladder stones, and removal and analysis of the stones themselves are necessary to identify their mineral composition as calcium oxalate. This is important because different stone types require different measures to decrease their risk of recurrence.

Treatment of Calcium Oxalate Bladder Stones in Dogs

Surgical removal is usually recommended for calcium oxalate stones. Some veterinarians may also be equipped to use urohydropropulsion, which is a procedure that flushes the stones out of the bladder using a special catheter.

A referral center may have the ability to attempt ultrasonic dissolution, a process where ultrasound is used to break the bladder stones into tiny pieces that can be flushed out.

After the stones are removed, a special prescription diet may be necessary. The dog should be encouraged to drink plenty of water, which can sometimes be accomplished with the use of a pet fountain. The veterinarian may recommend routinely checking x-rays for recurrence of stones.

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