Crystals in Neutered Male Cats

Straining in the litter box could mean your furry friend has a urinary obstruction.
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Male kitties, neutered or not, can suffer from crystals in their urine, though crystals occur more frequently in fixed ones. Crystals in the urine are dangerous to cats, causing infection and inability to urinate. They require veterinary care and diagnosis to properly treat.

Neutering and Crystals

While in the past many vets believed that neutering a kitty narrowed his urethra, this actually isn't the case, according to a 2005 article published in "Veterinary Clinics of North America: Small Animal Practice." Both neutered and non-neutered kitties naturally have very narrow urethras that can easily become blocked by crystals that have formed in the urine, more easily than in females. Neutered kitties do tend to experience more frequent urinary infections than non-neutered ones. These urinary infections lead to inflammation of the bladder known as cystitis and the formation of crystals in the urine, according to the VetInfo website. These crystals can plug up his urethra if they become stuck when he urinates. This then leads to a buildup of urine in his bladder, a potentially life-threatening situation that needs immediate veterinary attention.

Types of Crystals

The two most common types of crystals, also referred to as urinary calculi, in the bladder are either struvite and calcium oxalate ones, according to the American Society for the Prevention of Cruelty to Animals. In general, neutered male kitties tend to suffer more from calcium oxalate crystals than struvite ones. In fact, they are less prone to struvite crystals than female kitties, according to an article published in the February 1996 issue of the "Journal of the American Veterinary Medical Association." While struvite crystals can be treated and prevented through dietary changes, calcium oxalate crystals may require surgical removal in some cases. To help prevent both types of crystals, provide plenty of fresh water for your furry friend to help flush out any chemicals and bacteria that can lead to the formation of these crystals in the urine.

Visiting the Vet

If you suspect your furry friend is suffering from crystals in his urine, a condition known as urolithiasis, bring him to the vet for an exam. Signs of crystals in the urine include straining while in the litter box, blood in the urine, crying while urinating or more frequent urination than usual, according to the Bay Park Veterinary Clinic. He may also start urinating outside of his litter box, which is unusual for neutered male kitties because they don't usually tend to spray urine like intact males do. Your vet will give him a physical exam and perform a urinalysis to test for the presence and type of crystals in the urine, along with any bladder infections present. She may prescribe antibiotics in some cases and if a blockage is suspected, she will likely hospitalize your kitty to administer intravenous fluids and catheterize your furry friend to clear the obstruction.


Early neutering, performed between 7 and 8 weeks of age was once thought to be a cause of crystals in the urine of neutered kitties, later in life. However, this has been shown not to be the case, according to the Namcha Home for Wayward Animals. The benefits to neutering outweigh the risks, preventing unwanted litters of kittens and behavioral problems. To discourage any crystals from forming in your neutered little boy's urine, provide him with tempting sources of refreshment, like a pet fountain, to attract his interest and keep him drinking plenty of fresh water. Canned food contains a large amount of water, up to 80 percent, which can help your furry friend get the water he needs in his diet to properly dilute his urine, recommends the petMD website. Consult with your vet to see if a prescription diet to adjust the pH of his urine might also be needed for your kitty, depending on the types of crystals he suffers from.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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