Hill's Prescription Diet c/d Urinary Care Cat Food

This is a prescription diet, and that matters

The most important thing on this page: therapeutic urinary diets are veterinary diets. They are formulated to alter urine chemistry, and they should be used for a cat your vet has diagnosed and is monitoring.

That is not a formality. These diets work by changing mineral levels and urine acidity, and the right choice depends entirely on which type of crystal or stone your cat has — the two common types need opposite conditions. Feeding the wrong urinary diet can make the wrong problem worse.

Your vet identifies which it is from a urine sample and imaging. That is a lab result, not something visible in the litter box.

Struvite and calcium oxalate are opposites

Struvite stones form in urine that is too alkaline. Some struvite stones can be dissolved medically with a diet that acidifies the urine and restricts the minerals involved — which is what a dissolution diet is for, and it is one of the few conditions in veterinary medicine where a food genuinely treats rather than manages.

Calcium oxalate stones form in urine that is more acidic, and they cannot be dissolved. They have to be removed surgically or by other means, and diet is then used to reduce recurrence.

So "urinary food" is not one thing, and buying one off a shelf because a cat had a urinary episode is a real way to cause harm. Duration matters too: dissolution diets are usually fed for a defined period under monitoring rather than indefinitely.

The emergency nobody should miss

A male cat straining in the litter box and producing little or nothing is a suspected urethral blockage. That is life-threatening and needs a vet immediately, including out of hours. Blocked cats can die within a day or two.

Signs: repeated trips to the box, straining, crying, licking at the genitals, vocalising, a hard painful abdomen, vomiting, collapse. Male cats are at far higher risk because the urethra is narrower.

No food, supplement or litter addresses a blockage. Go to a vet.

Most urinary disease in cats is not stones

Worth knowing, because it changes what helps. The largest share of feline lower urinary tract signs is feline idiopathic cystitis — bladder inflammation with no identifiable infection or stone. It is strongly associated with stress, and it flares and settles.

For that, the things that help most are environmental:

A therapeutic diet is part of a plan for some cats and not the whole answer for most.

Practical notes on feeding a therapeutic diet

Who should look elsewhere

If your cat has not been diagnosed, start with a vet and a urine sample, not a bag. If the diagnosis is calcium oxalate rather than struvite, this is the wrong diet. And if your cat is straining and producing nothing, stop reading and go to a vet now.