Royal Canin Urinary SO is a veterinary diet for adult cats with urinary problems such as struvite crystals or stones. It is designed to dilute the urine and change its mineral balance, and it should be fed only on your vet’s advice.
What Urinary SO is for
Royal Canin makes Urinary SO in dry and wet forms. Veterinarians use it to help dissolve struvite stones and to reduce the risk of struvite and calcium oxalate crystals in cats. Making cats drink and urinate more dilutes the urine, which makes crystals harder to form. Ask your vet whether it suits your cat’s condition, since different stones need different approaches.
How it works
- Dilute urine: higher sodium and a formula that encourages drinking increase urine volume.
- Controlled minerals: the levels of minerals involved in stone formation are managed.
- Urine pH control: the food helps keep urine in a range that discourages crystals.
Who should (and should not) eat it
Urinary SO is a therapeutic diet, so it needs a prescription or vet authorization. It is not an everyday food for healthy cats, kittens or pregnant cats unless your vet says so. Cats with kidney, heart or blood pressure issues may need a different plan, because some urinary diets are higher in sodium.
Feeding tips
- Follow the feeding guide on the package and your vet’s instructions.
- Switch gradually over about a week to avoid stomach upset.
- Feed it alone. Treats and other foods can undo the diet’s effect.
- Give plenty of fresh water. Water fountains and wet food can help.
- Have urine rechecked on the schedule your vet recommends.
Cost and alternatives
Prescription urinary diets cost more than regular cat food. Other brands also make veterinary urinary diets. Ask your vet before switching. See also our guides to Royal Canin Urinary Care for cats and the best pouch food for wet cats. If your dog needs a similar diet, see Royal Canin Urinary SO for dogs.
Warning signs: call a vet immediately
A male cat who strains to urinate, passes little or no urine, cries in the litter box or licks his genitals may have a blocked urethra, which is life-threatening. Go to a vet immediately. Other signs include blood in the urine, frequent small urinations or urinating outside the box. This is general information, not veterinary advice.
Bottom Line
Royal Canin Urinary SO can help cats with certain urinary stones and crystals, but it is a prescription-style diet. Use it only with your vet’s guidance and watch for emergency signs.
