Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

What Are Struvite Crystals in Cats? Our Vet Explains Causes & Treatments

Urine sediment showing Struvite crystals

If you notice any changes in your cat’s urination habits, this could be a sign of an issue with the urinary tract and could be struvite crystals. This problem could be resolved with a vet-developed diet or result in surgery. Let’s look at what you should know about preventing and treating struvite crystals.

divider 3 paws

What Are Struvite Crystals?

Struvite crystals form within the urinary tract. They are a combination of phosphate, magnesium, and ammonium. While you might find low numbers of struvite crystals in normal urine, they can also indicate or lead to bladder problems, such as bladder stones.

What Are the Signs of Struvite Crystals in Cats?

Struvite crystals can be an incidental finding on a urinalysis, but they can also be associated with urinary tract infections. As such, signs of struvite crystals include:

  • Increased frequency of urination (pollakiuria)
  • Blood in urine (hematuria)
  • Straining to urinate (stranguria)
  • Inappropriate urination
  • Crying, especially when trying to urinate

Some pets with urinary tract infections can be lethargic or have a decreased appetite. So, it’s always worth it for your veterinarian to check a urinalysis if your cat is acting “off.”

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

Struvite crystals can be associated with urinary blockages, particularly in male cats. They are at a higher risk for blockages because their urethra is longer and narrower, so it’s easier for crystal clumps, mucus, and even stones to block the passage of urine.

A urinary obstruction can be life-threatening. There are a few consequences of a urinary blockage. First, the bladder can distend and rupture. Cats can develop kidney failure. Electrolyte imbalances are possible, and if your cat can’t urinate, their potassium levels may increase. If they get too high, cardiac arrhythmias are possible, particularly bradycardia or low heart rate.

black and white cat peeing outdoor
Image Credit: nanniezwawa, Shutterstock

divider 3 paws

What Are the Causes of Struvite Crystals in Cats?

In dogs, struvite crystals are commonly associated with urinary tract infections. We don’t see that as commonly in cats, but it’s still possible. In these cases, bacteria produce urease, which decreases the pH of the urine and makes it more likely for struvite crystals to form.

Struvite crystals may form if the urine is very concentrated. Cats that don’t drink as much water tend to have more concentrated urine and may have a higher risk of struvite formation. Your cat’s diet may cause a more alkaline or basic urine pH, which might cause crystals. Your cat is also at a higher risk if their diet produces more magnesium or phosphorus in their urine.

Sick sad cat lying on the bed
Image Credit: Zhuravlev Andrey, Shutterstock

Diagnosing Struvite Crystals in Cats

Your veterinarian may perform a urinalysis as part of a routine physical exam before anesthesia or as a secondary to urinary or behavioral issues noted at home. Struvite crystals are readily seen under the microscope and may vary in size but have roughly the same basic shape as a coffin lid.

Your veterinarian might see other findings on the urinalysis, such as red blood cells, white blood cells, and bacteria.

They'll check for other things, as well, such as:
  • How well your cat is concentrating its urine
  • Protein levels
  • Other crystals

Your veterinarian may run the urinalysis in the hospital or send it to a lab for analysis. They may also recommend culturing the urine. Some hospitals even have automatic analyzers that scan the urine and spit out a report faster than humans.

Other tests to assess your cat's bladder health include:
  • Blood work, including a complete blood cell count and biochemistry
  • Ultrasound
  • Radiographs (X-rays)

divider 3 paws

How Do I Care for a Cat With Struvite Crystals?

If your cat has bladder stones associated with their struvite crystals, you and your veterinarian might decide to perform surgery, a cystotomy.

However, in many cases, you don’t have to resort to a cystotomy. Dissolving the crystals and stones is often an option. Your veterinarian will prescribe a specific diet, usually Hill’s c/d or Royal Canin SO, designed to support bladder health and dissolve stones. The important thing to bear in mind is that this diet is usually lifelong. Cats that develop struvite crystals are more likely to develop them again in the future, so dietary management is key. Your cat won’t be able to eat anything but the food, so everyone in the house will need to be on the same page.

Typically, struvite crystals will dissolve within a couple of months. Your veterinarian must monitor the dissolution process with repeat X-rays and urinalysis.

persian cat checked by vets
Image Credit: Beach Creatives, Shutterstock

If your cat has evidence of a urinary tract infection, your veterinarian will prescribe antibiotics. Some cats also need anti-inflammatory medications, such as Onsior.

If your cat stops urinating or is straining to urinate, they need to be evaluated by a veterinarian immediately. In the case of a urinary obstruction, your cat will usually be sedated and have a urinary catheter placed. They may be hospitalized for several days with fluid therapy and medications.

Some cats with an obstruction, especially if they obstruct more than once, may need a perineal urethrostomy, where a larger surgical opening is made to help unblock them.

divider 3 paws

Preventing Struvite Crystals in Cats

If your cat has had urinary crystals, your veterinarian is likely to recommend keeping them on a diet to dissolve struvite crystals. These diets tend to restrict the levels of magnesium and phosphorus. They also help acidify the urine, which decreases the pH, making the formation of struvite crystals less likely.

Some cats are prone to urinary issues when stressed or have anxiety. Your veterinarian might suggest Hill’s c/d MultiCare Stress to help with urinary and stress issues.

You’ll also want to make sure your kitty drinks plenty of water. The easiest way to do this is to give them canned food every day or add water to their food. You might also try using a water fountain, although not all cats will use them.

Your veterinarian will likely recommend regular urinalysis rechecks. If they ask you to collect a sample using non-absorbable litter at home, you’ll want to bring it in immediately for evaluation. Struvite crystals can spontaneously form when urine sits out for an extended period, so collect it and bring it right in, or keep it in the fridge until you bring it in.

cat eating wet tuna food
Image Credit: Svetlana Rey, Shutterstock

divider 3 paws

Frequently Asked Questions

Can Dry Food Cause Struvite Crystals in Cats?

Yes, dry food may increase the possibility of your cat developing struvite crystals because they may not be drinking enough water. Feeding canned food can help with that.

Can Tap Water Cause Struvite Crystals in Cats?

In some cases, tap water might be linked to forming crystals, especially if the water is high in magnesium. If the water is high in calcium, it could cause other crystals. That said, diet is the more likely reason for crystal formation.

divider 3 paws

Conclusion

Struvite crystals can form in cat urine for different reasons, including urinary tract infections and highly concentrated urine. Your veterinarian can help determine the crystals’ significance and recommend treatment, such as diet change.


Featured Image Credit: Pee Paew, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

8 Pet-Friendly Hotels in San Antonio, TX (2025 Guide)

San Antonio may be best known for the Alamo and its history, but it’s drawn from that history and modern cosmopolitan tastes to...

Guide to Dry Skin on Cats: 9 Vet-Reviewed Causes & Treatments

Cats can suffer from dry skin just like we do. Dry skin can be uncomfortable, itchy, and irritating, so it’s best to figure...

My Cat Ate a Dryer Sheet! Vet Reviewed Information & What to Do!

As cat parents, we all know that cats are curious, mischievous, and can get into any number of things they shouldn’t. That includes...

Can Cats Eat Feathers? Vet-Reviewed Risks & Precautions

Feathers are included in various enticing cat toys, most likely because they are reminders of favorite prey animals of felines: birds. Whether a...

More related

How Long Does It Take for Cat Hair to Grow Back? Vet Verified Facts & FAQ

Whether your kitten just had surgery, your long-haired cat has undergone regular grooming, or you’ve taken a rescue cat that needed shaving to...

Five Freedoms of Animal Welfare: How Vets Apply Them to Cats

It may be hard to imagine a time when drafting the principles of basic animal care was necessary. Sadly, the inhumane treatment of...

Can Cats Drink Orange Juice? Vet-Reviewed Nutrition Facts & FAQ

Some people like to share certain safe foods with their cats, and most consider orange juice healthy and nutritious, so it’s only natural...

Lykoi (Wolf Cat) Health Problems: Our Vet Explains 5 Common Issues

Lykoi cats are also known as wolf cats or werewolf cats. Since the breed’s development, they have become increasingly popular, but you may...

Keep reading

My Cat Won’t Eat: Causes, Feeding Recomendations & When To Worry (Vet-Verified)

Cats are pretty good at hiding it when they aren’t feeling well, and a sudden lack of interest in eating is a cause for concern. Cats can go off their food for many reasons, from stress to dental pain and...

Tabby cat eating food from white bowl

Are Oriental Shorthair Cats Hypoallergenic? Vet-Verified Breed Facts & FAQ

The Oriental Shorthair is a stylish and energetic cat breed that can bring joy and companionship to any home. If you have allergies, you might wonder if they are hypoallergenic. All cats produce allergens, mainly through their saliva, skin, and...

close up oriental shorthair cat

Normal Cat Blood Pressure: Vet-Approved Information & Facts

As pet parents, we want only the best for our feline friends. However, many cat owners don’t realize that, much like humans, cats can also suffer from problems with their blood pressure. The normal blood pressure range for your feline...

checking blood pressure of cat

Congestive Heart Failure in Cats: Vet-Reviewed Facts & When to Euthanize

Being a cat parent comes with many ups and a few unfortunate downs. We do our best to take care of our cats so they can live long and healthy lives, but health conditions can creep up when we least...

a red long-haired tabby cat is being checked up by a vet

Cat Blood Test Results Explained – What Should I Look For?

Sometimes, cats show signs of an illness or disease, but a confirmed diagnosis isn’t possible without blood tests. Blood tests have a wide range of uses in veterinary medicine. They can help verify the good health or illness of a...

cat blood sample

Do Air Purifiers Help With Cat Allergies? Vet Reviewed Facts & FAQ

Though around 70% of U.S. households have a pet, many people suffer from animal allergies.1 A whopping 10 to 20% of the world’s population has allergies to cats and dogs. If you’re part of these statistics and want to live...

Close up of a Fluffy Cat Sitting Next to Air Purifier

Why Does My Cat Chirp at Birds? 3 Vet-Verified Common Reasons

Your cat may seem like a cuddly ball of fur or even a hairless wonder who loves to spend time with you under the blankets, but something changes when your feline sees a bird outside the window. Instantly, your kitty...

cat watching bird on the window

Can I Take My Cat to the Beach? 6 Vet-Reviewed Tips and FAQ

A fun day at the beach is the perfect way to spend an afternoon, and it’s common to see dog lovers with their furry friends on the beach running along the shoreline. We know that some beaches don’t allow dogs,...

woman and her cat in the beach