What you need to know about urinary crystals in cats

A small number of urinary crystals is common and normal in cats, and they usually pass without issue. They may become problematic in large concentrations, as they can irritate the bladder and urethra, cause inflammation, and lead to a life-threatening urinary blockage. If you have a cat, read on to learn:

• How do urinary crystals in cats form?
• How do I know if my cat has crystals or an obstruction?
• Do urinary crystals need treatment from a vet?

When they cause problems, crystals can lead to symptoms such as frequent urination and trips to the litter box, blood in the urine, and straining to urinate. Treatment varies depending on the type of crystal, the severity of symptoms, and the underlying cause. When needed, treatments may include flushing the urinary tract to remove crystals, a change in diet, decreasing stress, increasing water intake, and hospitalization to treat urinary obstructions.

Urinary crystals form due to the chemical composition of a cat’s urine. Sometimes, the minerals that form urinary crystals stay dissolved in the urine. Other times, they can become solid, forming microscopic crystals in the urine. These small crystals can stick to each to form larger clumps of crystals or bladder stones, which can be seen with the naked eye. Crystals are microscopic, so they often pass in a cat’s urine without difficulty. However, even though they’re tiny, urinary crystals are abrasive and can irritate the bladder wall or urethra, leading to symptoms such as bloody urine and straining to urinate. Crystals and stones can collect in the urethra and cause a life-threatening urinary obstruction, especially if there is a high concentration of crystals in the urine. The risk for urinary obstruction is higher in male cats because they have narrower urethras.

It’s normal to find crystals in cat urine, but sometimes they cause symptoms. Small amounts of crystals in cats typically pass without difficulty. Large concentrations of urinary crystals are more likely to cause bladder inflammation, irritation, or urinary obstructions. Urine crystals won’t always cause clinical signs, but when they do, they may include:

• Blood in urine
• Spending a lot of time in the litter box
• Frequent urination, often in small amounts
• Straining to urinate
• Urinating outside of the litter box
• Painful urination or vocalizing when urinating

Straining unproductively, or not being able to urinate, is a medical emergency that needs immediate veterinary care. It can be difficult to know if a cat is straining unproductively if the amount of urine being produced is too small to detect. If you’re unsure whether your cat is straining unproductively or only urinating in small amounts, it’s best to seek veterinary attention.

What are the signs of a urinary obstruction?

Urinary obstructions occur when the urethra becomes blocked by an accumulation of crystals, stones, or mucus. Male cats are at a higher risk of obstruction due to a longer and more narrow urethra compared to female cats.

Obstructions don’t usually develop until there’s a large concentration of crystals and the urethra is inflamed. At this point, your cat has likely shown urinary symptoms for a few hours to a few days.

Obstructions can be partial— allowing tiny amounts of urine to pass — or complete. Urethral obstructions become rapidly life-threatening and lead to kidney failure, often in 24 hours or less. Additional symptoms of urinary obstruction in cats include:

• Vomiting
• Lack of appetite
• Lethargy
• Weakness

Crystals in cat urine can be seen under a microscope during a urinalysis. Sometimes they can be seen during an ultrasound of the bladder. The presence of urinary crystals while your cat shows no other urinary symptoms is not an illness; crystals may be found during routine wellness testing without being a cause for concern. If your cat is showing signs of urinary problems, however, diagnostic tests may be suggested, including:

• Physical exam
• Urinalysis and urine culture
• Abdominal X-rays or ultrasounds
• Blood tests

Other urinary conditions, such as urinary tract infections, feline idiopathic cystitis, and bladder stones, have similar symptoms and need to be ruled out as underlying problems.

Sometimes cats have crystals in their urine without any other urinary symptoms. “The presence of crystals is not what determines if treatment is necessary,” explains Dr. Jo Myers, a veterinarian on Vetster. “Cats with urinary crystals are generally only treated when the crystals are causing irritation and inflammation or the cat is at risk for urethral obstruction.” Urinary crystals can have different chemical compositions, so the type of crystal may affect the treatment plan.

Treatments for problematic crystals in cat urine may include:

• Flushing the bladder to expel crystals
• Diet modification
• Fluid therapy or increasing water intake at home
• Decreasing stress
• Symptomatic care

Urinary obstructions require immediate veterinary treatment, which may include:

• Flushing the urethra
• Surgery
• Hospitalization with a urinary catheter to allow urine to pass while the urethra heals

Vets usually recommend hospitalizing a cat with a urinary blockage for at least two days. Hospitalization allows a veterinarian to:

• Provide IV fluid therapy, antibiotics, and pain medication
• Ensure the flow of urine is back to normal
• Check kidney function

When a cat goes home, close monitoring is advised because re-obstruction is common. Medications or special diets may be recommended for long-term treatment to decrease the likelihood of obstructions in the future.

Do cats with urinary crystals need treatment?

Not all cats with urinary crystals will need treatment. The presence of microscopic crystals in cat urine is normal. However, abrasive crystals can irritate the bladder and urethra, causing inflammation and leading to symptoms. A buildup of crystals can become lodged in the urethra, causing a life-threatening obstruction. Most cats with urinary crystals are only treated if they have other urinary symptoms or to prevent a urinary obstruction.

Can I treat my cat’s urinary crystals at home?

There may be some steps cat owners can take to help avoid problems related to urinary crystals. Some types of crystals that cause problems can be prevented with a urinary therapeutic diet. Talk to a vet to learn more about the role special diets play for cats who:

• Produce a lot of crystals in their urine but have never had symptoms
• Have had a bout of feline lower urinary tract disease related to crystals, including obstructions
• Have never had urinary issues

Cats experiencing urinary symptoms such as straining, bloody urine, spending a lot of time in their litter box, or only producing small amounts of urine need veterinary attention as quickly as possible.

Talk to a veterinarian any time your cat is experiencing urinary symptoms. There are many urinary conditions that share clinical signs that vary in severity. An accurate diagnosis is needed to determine an effective treatment plan. It’s best to seek veterinary care if you think your cat might have a urinary obstruction, as it is a medical emergency and can cause irreversible and fatal kidney damage very quickly.

It isn’t always easy to tell whether your cat is straining unproductively to urinate or if they are straining and urinating in small amounts. Both straining and unproductive straining are serious symptoms that require a vet visit, but unproductive straining is an emergency that requires immediate veterinary attention. If you’re unsure whether your cat is straining unproductively to urinate or if you have any other concerns about recurring urinary issues, talk to an online vet through the Vetster platform today.

How do vets treat problematic crystals in cats?

Not all urinary crystals show symptoms or require treatment. When treatment is needed, it may include, flushing the bladder to expel crystals, stress management,  a diet change, increasing water intake through wet food and placing more water bowls or fountains around the home, and symptomatic care.

Does cat food cause urinary crystals?

For some cats, food that’s high in certain minerals increases the number of urinary crystals. Finding crystals in cat urine is normal, but cats with a large number of crystals are at risk for urinary tract irritation, inflammation, and blockage. For cats prone to urinary issues or who produce a lot of crystals, a prescription diet may be recommended by a vet. Urinary or prescription diets are not necessary for all cats.

Are crystals in cat urine serious?

Finding crystals in cat urine is normal and often incidental while testing for something else. Urinary crystals become problematic when they accumulate and cause symptoms associated with urinary tract irritation, inflammation, and blockage.