How to detect and treat bladder stones in cats

Bladder stones in cats are common. While some stones can pass on their own, others lead to symptoms such as bloody urine, painful urination, straining to urinate, and frequent urination. Stones can become lodged and cause a urinary obstruction, which is an emergency. If you have a cat, read on to learn:

• How bladder stones in cats form
• Symptoms of bladder stones
• When bladder stones are an emergency
• How bladder stones are diagnosed and treated by a vet

In many cats with bladder stones, other lower urinary tract diseases, such as idiopathic cystitis or urinary tract infections, are present. It’s important to seek veterinary care when a cat has urinary symptoms for an accurate diagnosis and effective treatment plan.

Bladder stones in cats are clumps of minerals that form from urine in the bladder. Urinary stones can vary widely in size and mineral composition. The most common types of stones that form in cats are calcium oxalate stones and struvite stones. Stones are very common in cats and form when certain conditions are present in the urine. Urinary stones can also form in the kidneys, but kidney stones in cats are far less common than stones in the bladder.

How bladder stones in cats form

Different types of minerals are naturally found in a cat’s urine. When the concentration of minerals in a cat’s urine exceeds a certain threshold, they separate out, forming microscopic crystals. Over time, urinary crystals aggregate together to form stones that are visible to the naked eye. Various factors increase a cat’s risk of developing bladder stones, including:

• Composition of their diet
• Changes in urine pH level
• Urine concentration
• Bladder inflammation or infection

The development of stones in cats is not fully understood, but it is likely that multiple factors play a role.

Small stones may pass through a cat’s urinary tract with few to no symptoms. Larger stones can irritate the urinary tract or even interfere with normal urination and lead to symptoms that include:

• Bloody urine
• Frequent urination, often in small amounts
• Straining to urinate
• Pain or vocalization when urinating
• Urinating outside of the litter box
• Overgrooming the genitals
• Urine with a foul or strong odor
• Abdominal pain

Straining to urinate is often mistaken for straining to defecate, as the symptoms look very similar. However, straining in the litter box is more likely to be a urinary problem than a fecal problem. You can speak to your vet about differentiating the symptoms if you’re unsure whether your cat is straining to urinate or defecate.

If a stone passes on its own, symptoms usually subside. However, stones can block the flow of urine through the urethra, causing an inability to urinate. This is a medical emergency that requires immediate veterinary attention. Cats who develop urinary blockages usually have urinary symptoms prior to the block.

Bladder stones are not an emergency, but they can cause emergency complications. Urethral obstructions caused by larger stones getting lodged in the urethra require emergency treatment. If a cat cannot urinate, acute kidney failure can result within a couple of days. Symptoms of urinary blockages include:

• Straining unproductively to urinate
• Vocalization and distress when trying to urinate
• Spending a lot of time in the litter box
• Vomiting
• Lethargy
• Lack of appetite

Urinary blockages and their symptoms progress rapidly if they are not treated.

Urinary stones are common in cats and do not always cause symptoms. If a cat has urinary symptoms, a veterinarian will likely recommend urine tests after a physical exam and discussing their symptoms. Some stones may be felt when a vet palpates the abdomen during the physical examination. A vet may recommend:

• Urinalysis and urine culture
• Bloodwork
• Diagnostic imaging, such as X-rays or ultrasounds

Urinary stones are visible to the naked eye, so they may be identified when a cat passes one or when they are visible on an X-ray or ultrasound. Additional urinary tests and a stone analysis may help identify the underlying cause of the stones.

Options for treatment vary depending on the underlying cause, size, and type of stone. Some bladder stones do not need treatment because they either remain in the bladder or pass without causing problems. Sometimes stones may be left in the bladder until they become a problem. If treatment is needed, options may include:

• Flushing the urinary tract to remove stones
• Surgical removal of stones
• Pain medication
• Dietary modification
• Antibiotics

Struvite stones can be dissolved with dietary therapy. Calcium oxalate bladder stones cannot be dissolved and require a different method of treatment. Antibiotics don’t treat bladder stones, but may be indicated if an infection is present. The prognosis for bladder stones is good in the majority of cases.

If a cat has a urinary obstruction, additional treatment is needed. Treatment for urinary obstructions may include:

• Flushing stones from the urinary tract
• Surgical removal of stones
• Hospitalization for urinary catheter placement, IV fluids, antibiotics, and close monitoring

Cats who have had stones or urinary tract obstructions in the past are likely to have them again. A therapeutic diet is often part of the long-term management plan for cats with bladder stones.

Can I treat my cat’s bladder stones at home?

It is important not to attempt to diagnose or treat your cat’s urinary issues at home. Different types of urinary conditions have similar symptoms and misdiagnosis is likely. Inappropriate or delayed treatment for these conditions can be life-threatening. Multiple urinary issues can be present and interconnected such as stones, bladder infections, and obstruction. “Depending on the situation, treatment for a cat’s bladder stones may not be necessary,” explains Dr. Jo Myers, a veterinarian on Vetster. “However, if you find a bladder stone that your cat has passed, it’s best to have the stone submitted for analysis and see a vet to learn more about the nature of your cat’s problem. Once an accurate diagnosis is made, then it’s possible to know how to treat the stones.”

Some stones cannot be treated at home and require care in a veterinary hospital. Others can be managed at home, often with a special diet. Since a bladder stone might become lodged in the urethra at any time, it’s important to keep an eye out for signs of an obstruction throughout treatment.

Bladder stones in cats cannot always be prevented, but there are a few factors that increase the risk of stone formation. Risk factors include:

• Diet characteristics
• Dehydration
• Other urinary issues
• Previous stones or urinary crystals
• Obesity
• Sedentary lifestyle
• Stress
• Certain medications

Male cats are most at risk for urethral obstructions due to a longer, thinner urethra where stones are more likely to become lodged. Other urinary conditions in cats are common. Up to a quarter of cats with other lower urinary tract diseases are affected by stones in the bladder.

Talk to a vet anytime your cat exhibits urinary symptoms. The symptoms may be caused by bladder stones or another health condition within the urinary tract. A cat who is straining to urinate and producing only small amounts of urine or no urine at all may have an obstruction, which is an emergency. While these symptoms also occur with other lower urinary tract diseases, it’s best to seek veterinary care just in case it is a urinary blockage. Talk to a vet if your cat has had urinary issues in the past and find out how you can help with long-term management. If you would like to speak to a veterinary professional about your cat’s urinary health, you can book a virtual vet appointment through Vetster at any time.

What food causes bladder stones in cats?

There isn’t a specific food or type of food that causes bladder stones. While a cat’s diet influences the composition of their urine, many other factors contribute to the formation of stones. Even if a therapeutic diet is recommended for a cat diagnosed with stones, this does not mean the cat’s stones were caused by its diet.

Will stones in cat urine go away on their own?

Some small bladder stones can pass through the urinary tract on their own without any issues. If a cat is having urinary symptoms associated with urinary stones, it’s best to seek veterinary care for diagnostic testing. Urinary stones that cannot pass on their own can lead to life-threatening urethral obstructions.

What are the symptoms of bladder stones in cats?

Bladder stones are often asymptomatic. Blood in urine, frequently urinating in small amounts, painful urination, straining to urinate, and overgrooming the genitals may occur if bladder stones are causing problems, but these symptoms also occur with other forms of lower urinary tract disease. A cat with urinary stones may also urinate outside of the litter box or vocalize while trying to urinate. Seek medical care right away if a cat is unable to urinate and straining unproductively.