Provides nutrition that aids the management of pure struvite uroliths

Increasing the urine volume reduces the saturation of urine with calcium oxalate and struvite crystals

Relative Supersaturation (RSS) methodology predicts the crystallization potential of urine. RSS is used to develop diets that lower the concentration of ions contributing to struvite and calcium oxalate urolithiasis

Reduced level of magnesium, a natural component of struvite stones

Specially formulated to assist in the management of lower urinary tract disease in cats.

Working toward a sustainable future

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Labrador Retriever adult sitting with its owner outdoors

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

Calorie Content

This diet contains 3645 kilocalories of metabolizable energy (ME) per kilogram or 313 kilocalories ME per cup on an as fed basis (calculated).

Crude Protein (min)32.5%, Crude Fat (min)13.0%, Crude Fiber (max)4.9%, Moisture (max)7.5%, Calcium (max)1.13%, Phosphorus (max)1.26%, Magnesium (max)0.07%.

Dry Feeding

Weight Normal Overweight
4.4 lb (2 kg) 3/8 cup (33 g) 1/4 cup (26 g)
6.6 lb (3 kg) 1/2 cup (44 g) 3/8 cup (35 g)
8.8 lb (4 kg) 5/8 cup (54 g) 1/2 cup (43 g)
11 lb (5 kg) 3/4 cup (63 g) 5/8 cup (50 g)
13 lb (6 kg) 7/8 cup (72 g) 5/8 cup (57 g)
Royal Canin Veterinary Diet Feline Urinary SO Dry Cat Food

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Customer reviews

Ben T
06 Apr 2024

Vomiting brownish liquid + Hairballs each week

Urinary s/o ultra low quality food, vomiting brownish/gold liquid + hairballs weekly all over the house for two years. Feeling stupid that I fed my cat with this for two years, i thought I was going crazy, he was throwing up 2-3 times a week. Been feeding him with Hill's Science Diet for a month now and NO VOMIT, NO HAIRBALLS AT ALL plus he have much more energy. There is something awful with this recipe.
28 Jan 2024

SO saves our vet bills

We have been using Urinary SO for 10 years, we live out in rural Virginia where a lot of cats show up as abandoned so we take them in since the shelters are full. All the cats have to eat the SO so it gets rather expensive, but less expensive then the kitties getting bladder issues. Help can we buy SO by the pallet?
12 Jan 2024

Vomiting issues.

My cats been puking up his food for the past bit and I now see comments saying it's because you changed the recipe?! Why is it making so many cats vomit now?! This is seriously not ok.
10 Jan 2024

Recent Formula Change is BAD

Why was this formula recently changed??! My cat has been on this over a decade and now suddenly you add egg product and he's puking it up and allergic to it. CHANGE IT BACK.
05 Jan 2024

Urinary-SO-gold-colored cat vomit everywhere

To add to the other 1-star reviews on vomiting, my cat has been on USO for many years and with the most recent batch (bought in late 2023) began vomiting it up daily. He has no other symptoms and is otherwise happy and normal, so I do heavily suspect that it's the RC USO. It's also a very expensive food. I will seek another brand because I'm tired of doing laundry washing sofa and chair covers of Royal Canin Urinary-SO-gold-colored cat vomit.
01 Jan 2024


My cat has been on this food for a couple months with no issues, however recently he has been vomiting every 2-3 days. After looking up if this is common with this brand of dry food I found it very much is. Something is off with this food, you can see every piece of kibble in his vomit which tells me it’s not being digested properly. I never had any issues with this when he was on Tiki Cat, unfortunately I had to switch due to urinary issues.
31 Dec 2023

Helped our cat but please read my whole review.

We have always fed our cats quality food and they had beautiful coats and great energy. But Our one cat started having a leaky bladder at a young age and after a visit to the vet this food was recommended. Yes the food fixed the bladder issue but the switch in food had a huge impact on our ragamuffins hair and energy level. You just have to read the ingredients to realize this is very very very low quality cat food with somthing in it to fix the cats urine issues. But what always bothered me was THE PRICE OF THIS CAT FOOD for what the ingredients are. Well thank god another large cat food maker started selling there version in Walmart. At least there first ingredient is chicken, now I'm not saying this other food is great but our cats hair an energy levels increase and still NO BLADDER ISSUES. And its 1/3 the price. So my advice is do some research and don't get sucked into the vet only overpriced food game :)
02 Nov 2023

Expensive but good

My cat has been on the SO FOOD ..kitty has kidney disease
21 Aug 2023

You'll be glad you did!

Our tuxedo, Sylvester, has been on RC Urinary SO Dry Cat Food for a few months. He's had a Blocked Tom twice now. The last episode was quite concerning and costly. He took to this catfood right away and hasn't had any issues since.
Royal Canin response
We are very happy to hear that our product has worked great for your cat. Thank you!
31 Jul 2023

Does not Work

My cat has struvite crystals and was prescribed this. He was using his litter box about 20 times a day before being put on this food due to the crystals. He has been on this food exclusively for a few weeks and is still using the litter box about 20 times a day. It is not working and cost a fortune. I do not recommend.