Bladder Stones in Dogs

What are bladder stones?

Bladder stones develop in the urinary bladder and are rock-like formations of minerals. Dogs often experience a mixture of small or large stones and they tend to form due to the disease or inflammation of the bladder. 

Types of bladder stones in dogs

Two of the most common types of bladder stones are struvite and calcium oxalate stones. 

Struvite stones are formed when struvite crystals (which aren’t found in normal urine) combine with certain bacteria. While the presence of struvite crystals doesn’t require treatment, when they combine with urease (a bacteria-produced enzyme) the formation of stones can occur. 

Calcium oxalate bladder stones in dogs can be formed due to hereditary reasons. This is due to some dog breeds producing defective nephrocalcin. This is a substance in urine that naturally forms calcium oxalate stones. Despite this being a genetic condition, these bladder stones can be caused by other factors. 

Symptoms of bladder stones in dogs  

Some common symptoms of bladder stones include:

• Difficulty and discomfort when urinating.
• Blood appears in urine.
• Cloudy or discoloured urine.
• Avoiding exercise. 
• Changes in their energy levels.
• Vomiting.
• Urinating frequently but in small amounts. 
• A bloated or sensitive stomach. 

Signs of bladder stones in dogs    

Common signs of bladder stones in dogs include:

• Blood in urine - This occurs when the stones rub against the bladder wall, causing irritation and damage to the tissue.  
• Straining to urinate - This happens because the bladder wall is inflamed and swollen. This can also cause muscle spasms. 

Stones can flow with the dog's urine causing them to become lodged and cause obstruction. An obstruction can be recognised when a dog isn’t producing any urine or is only producing small amounts. This can be a frequent problem for male dogs as their urethra (the neck of the bladder) is much longer and narrower. 

Bladder stones are considered as an emergency and are extremely painful, especially when pressure is applied to the abdomen. A rupture can occur if the bladder cannot be emptied. This is life threatening and requires immediate treatment. 

What causes bladder stones in dogs?

Bladder stones often occur as a result of mineral oversaturation and other factors like urinary tract infections or diet. 

How are bladder stones diagnosed in dogs?

Bladder stones can usually be palpated or felt with fingers through the abdominal wall. However, if bladder stones aren’t felt it doesn’t necessarily mean they aren’t there, as many stones are quite small or the bladder could be too inflamed to feel anything. 

Bladder stones can also be visible when using X-rays or undertaking an ultrasound exam. Some bladder stones can be radiolucent meaning they don’t show up on x-rays. However, ultrasounds should be able to detect them. 

How to prevent bladder stones in dogs

When it comes to bladder stone prevention in dogs one of the best methods is to keep them hydrated. Water reduces the chances of bladder stones forming and can help urinary crystals be flushed out or diluted. 

It’s recommended that an ounce of water per pound of body weight is drunk per day. The dog's water bowl should also be kept clean and filled with fresh water. Canned food can also help dogs stay hydrated. 

Bladder stones in dogs treatment    

Bladder stones can be treated through surgical removal, non surgical removal through urohydropropulsion and dietary dissolution. The treatment recommended will depend on the type of bladder stones a dog has.

Surgery

Surgery is the quickest way of removing bladder stones, however it’s not always the best option if the dog has any other medical conditions or concerns, or where general anaesthesia may be a worry. 

Removing stones through surgery is referred to as cystotomy. This involves opening the bladder in order to remove the stones. This is a routine surgery where most dogs heal quickly. 

Voiding urohydropropulsion

Urohydropropulsion is when a catheter is passed into the bladder to fill it and flush out the bladder stones. This treatment is used to help flush out small bladder stones. This procedure is performed under heavy anaesthesia, but general anaesthesia is often used as well. This procedure isn’t guaranteed to work and is less likely to in male dogs due to the anatomy of the urethra. 

Cystoscopy

Cystoscopy is a camera on the end of a long tube, which can be used to remove bladder stones without surgery. 

What dissolves bladder stones in dogs?

Dietary dissolution can be used in an attempt to dissolve bladder stones. This involves feeding a dog a special diet tailored to the specific type of bladder stone present in the dog. 

The most common diets that are often prescribed include:

• Hill's Prescription Diet C/D.
• Purina UR/StOX.
• Royal Canin Urinary SO.

While dietary dissolution can be successful, it does have some disadvantages:

• It’s not successful for all types of bladder stones. To identify the right diet the type of stone present in the dog's bladder must be determined. 
• It can take several weeks or even months for large stones to dissolve, meaning blood in urine, straining and recurrent infections may continue during this time. 
• These diets only work if they’re exclusively eaten. This means no treats or supplements can be provided during the diet.

FAQs

How quickly can bladder stones form?

Bladder stones can take between a couple of weeks and a couple of months to form. The rate of formation and growth will depend on the dog's diet, urine PH and the amount of crystalline material within their urine. 

How dangerous is bladder stone surgery in dogs?

Cystomy has very low risk complications as long as the dog is given proper time to heal and their stitches are protected during their recovery period. However, the most common complication is recurring bladder stones which can occur in 40% of dogs who have had surgery. 

Are bladder stones in dogs painful?

Bladder stones can be extremely painful, especially when pressure is applied to the abdomen.