HELPS DISSOLVE STONES: Innovative urinary tract cat food helps dissolve pure struvite stones and helps prevent calcium oxalate stones

BLADDER HEALTH: Lowers the risk of crystal formation using RSS methodology for cat bladder health

S/O INDEX: The exclusive S/O Index creates an environment unfavorable to crystal formation in the bladder to support urinary health

HELPS PREVENT STONE REOCCURANCE: Specialized diet, with a reduced level of magnesium, helps prevent struvite stones from reoccurring

When your cat has urinary issues, easing their discomfort requires special care. But with the help of your veterinarian and Royal Canin, there’s not just hope—there can be a true difference.

This veterinary-exclusive dry cat food was developed to nutritionally support your adult cat’s urinary tract and bladder health. It increases the amount of urine your cat produces to help dilute excess minerals that can cause crystals and stones. Relative Super Saturation (RSS) methodology is used to help lower ion concentration in urine, which contributes to stone formation. This formula promotes a urinary environment unfavorable to the formation of both struvite and calcium oxalate crystals. And this specialized nutrition, with a reduced level of magnesium, helps dissolve pure struvite stones and prevent struvite stones from forming. Lower urinary tract issues may be a recurring concern for some cats. Talk to your veterinarian about keeping your cat on this urinary cat food for long-term urinary support. And ask them about the right Royal Canin wet cat food and treats to complement your cat’s diet.

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Discover our tool that calculates the daily portion for your pet. Fill in your pet's information and you will get their daily feeding recommendation. In case of weight issues, do not hesitate to consult your vet to adapt this portion. Note that this feeding recommendation is more precise than the feeding table, therefore the values may slightly differ.


Chicken by-product meal, brewers rice, corn, corn gluten meal, chicken fat, wheat gluten, natural flavors, wheat, salt, powdered cellulose, fish oil, potassium chloride, sodium bisulfate, calcium sulfate, sodium pyrophosphate, vegetable oil, fructooligosaccharides, choline chloride, vitamins [DL-alpha tocopherol acetate (source of vitamin E), niacin supplement, biotin, riboflavin supplement, D-calcium pantothenate, pyridoxine hydrochloride (vitamin B6), vitamin A acetate, thiamine mononitrate (vitamin B1), vitamin B12 supplement, folic acid, vitamin D3 supplement], DL-methionine, taurine, monocalcium phosphate, trace minerals [zinc proteinate, zinc oxide, manganese proteinate, ferrous sulfate, manganous oxide, copper sulfate, calcium iodate, sodium selenite, copper proteinate], marigold extract (Tagetes erecta L.), rosemary extract, preserved with mixed tocopherols and citric acid.

Calorie Content

This diet contains 3659 kilocalories of metabolizable energy (ME) per kilogram or 315 kilocalories ME per cup on an as fed basis (calculated).

Nutrient Amount
Crude Protein (min)32.5%
Crude Fat (min)13.0%
Crude Fiber (max)4.0%
Moisture (max)8.0%
Calcium (max)1.26%
Phosphorus (max)1.26%
Magnesium (max)0.1%.

Dry Feeding

Cat Weight Low Activity Medium Activity High Activity
4.4 lb (2 kg) 1/4 cup (26 g) 3/8 cup (33 g) 1/2 cup (39 g)
6.6 lb (3 kg) 3/8 cup (35 g) 1/2 cup (44 g) 5/8 cup (52 g)
8.8 lb (4 kg) 1/2 cup (43 g) 5/8 cup (53 g) 3/4 cup (64 g)
11 lb (5 kg) 5/8 cup (50 g) 3/4 cup (63 g) 7/8 cup (75 g)
13.2 lb (6 kg) 5/8 cup (57 g) 7/8 cup (71 g) 1 cup (85 g)

Mixed Feeding

Cat Weight Cans / Day Low Activity Medium Activity High Activity
4.4 lb (2 kg) 1/2 1/4 cup (16 g) 1/4 cup (24 g) 3/8 cup (30 g)
6.6 lb (3 kg) 1 1/8 cup (15 g) 1/4 cup (26 g) 3/8 cup (35 g)
8.8 lb (4 kg) 1 1/4 cup (23 g) 3/8 cup (37 g) 1/2 cup (48 g)
11 lb (5 kg) 1 3/8 cup (31 g) 1/2 cup (47 g) 3/4 cup (60 g)
13.2 lb (6 kg) 1 3/8 cup (37 g) 5/8 cup (57 g) 7/8 cup (72 g)
Urinary SO Dry Cat Food

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Customer reviews

03 Jul 2022

Fantastic Food for our Male Cat!

When we adopted our cat he had problems with urine control. We tried several other products, stopped giving him food with fish in it, and nothing helped. He gained alot of weight and was freqently in pain and we had to go to the vet alot to relief the bloating pressure. Over a year ago the vet suggested using Royal Canin Urinary S0 dry food. Our cat is now at his normal weight and no longer has urinary tract issues.
17 Jun 2022

Very tasty

I bought this for my cats because they have Protein in the urine and it helps
16 Jun 2022

Cat love it

All our cats eat this even though only two really need it.
Amy B
01 Jun 2022

Saved my cat's life

I still think this food was necessary to save my cat when he had 3 urinary blockages in a row. He still has some kind of bacteria in his urine and also drinks bottled water. But when i've switched from this food he immediately starts getting sick
01 Jun 2022

Oliver 09
31 May 2022

31 May 2022

keeps my cat healthy

I use this dry food as well as the canned and it keeps his crystals low in his urine. However, his breed is Bombay and it hard to control his eating habits as there are two other cats in the house. It would be nice if the food was low cal.
31 May 2022

Crunchy texture and doesn't have sandy residue

I buy this regularly he has been on this since he was 4 is now 8. It would be nice if you had this in a senior formula.
31 May 2022

Good for health but lacks in taste

My cat hasn’t had any further complications since switching to this food after a blockage. However, he doesn’t eat as much as he used to.
02 May 2022

No Problems with Urinary SO food

My cat has crystals in her urine. Based on advice from our vet we switched to Royal Canin Urinary SO in March. She loves the small cans with gravy only found in 3oz sizes. She also likes the SO dry food. We have no problems with vomiting or diarrhea. She “toleratesl the 5oz cans but the consistency is different. However Finding Urinary SO in 3oz size is a challenge.