Relative super saturation (RSS) methodology predicts the crystallization potential of urine. RSS is used to develop diets for cats prone to both struvite and oxalate urolithiasis.

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

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Labrador Retriever adult sitting with its owner outdoors

Water sufficient for processing, pork by-products, pork liver, chicken by-products, chicken liver, chicken, pork plasma, powdered cellulose, wheat flour, natural flavors, wheat gluten, calcium sulfate, salt, fish oil, carob bean gum, carrageenan, potassium chloride, sodium tripolyphosphate, xanthan gum, taurine, sodium bisulfate, DL-methionine, vitamins [DL-alpha tocopherol acetate (source of vitamin E), thiamine mononitrate (vitamin B1), biotin, niacin supplement, D-calcium pantothenate, folic acid, pyridoxine hydrochloride (vitamin B6), riboflavin supplement, vitamin B12 supplement, vitamin D3 supplement], marigold extract (Tagetes erecta L.), trace minerals [zinc oxide, zinc proteinate, ferrous sulfate, calcium iodate, copper sulfate, manganous oxide, sodium selenite].

Calorie Content

This diet contains 820 kcal ME/kg; 119 kcal ME/can on an as fed basis (calculated).

Crude Protein (min)10.5%
Crude Fat (min)2.5%
Crude Fiber (max)2.0%
Moisture (max)81.0%.

Wet Feeding

Body Weight Tendency to be Overweight Ideal Weight
4.4 lbs (2 kg) 5/8 can (107 g) 3/4 can (133 g)
5.5 lbs (2.5 kg) 3/4 can (125 g) 1 can (156 g)
6.6 lbs (3 kg) 7/8 can (142 g) 1 1/8 cans (178 g)
7.7 lbs (3.5 kg) 1 can (159 g) 1 1/4 cans (199 g)
8.8 lbs (4 kg) 1 can (175 g) 1 3/8 cans (218 g)
9.9 lbs (4.5 kg) 1 1/8 cans (190 g) 1 1/2 cans (237 g)
11 lbs (5 kg) 1 1/4 cans (205 g) 1 1/2 cans (256 g)
13.2 lbs (6 kg) 1 3/8 cans (233 g) 1 3/4 cans (291 g)
15.4 lbs (7 kg) 1 5/8 cans (260 g) 2 cans (325 g)
17.6 lbs (8 kg) 1 3/4 cans (285 g) 2 1/8 cans (358 g)
19.8 lbs (9 kg) 1 7/8 cans (311 g) 2 3/8 cans (389 g)
22 lbs (10 kg) 2 cans (335 g) 2 1/2 cans (419 g)

Mixed Feeding

Weight Can + Overweight Normal Lean
4.4 lb (2 kg) 1/4 can + 1/8 cup (16 g) 1/4 cup (23 g) 3/8 cup (29 g)
5.5 lb (2.5 kg) 1/2 can + 1/8 cup (10 g) 1/4 cup (18 g) 1/4 cup (26 g)
6.6 lb (3 kg) 1/2 can + 1/8 cup (15 g) 1/4 cup (23 g) 3/8 cup (32 g)
7.7 lb (3.5 kg) 1/2 can + 1/4 cup (19 g) 3/8 cup (28 g) 1/2 cup (38 g)
8.8 lb (4 kg) 1/2 can + 1/4 cup (22 g) 3/8 cup (33 g) 1/2 cup (44 g)
9.9 lb (4.5 kg) 1/2 can + 1/4 cup (26 g) 1/2 cup (38 g) 5/8 cup (49 g)
11 lb (5 kg) 1/2 can + 3/8 cup (30 g) 1/2 cup (42 g) 5/8 cup (55 g)
12 lb (5.5 kg) 1/2 can + 3/8 cup (33 g) 1/2 cup (47 g) 3/4 cup (60 g)
13 lb (6 kg) 1/2 can + 3/8 cup (37 g) 5/8 cup (51 g) 3/4 cup (65 g)
14 lb (6.5 kg) 1/2 can + 1/2 cup (40 g) 5/8 cup (55 g) 3/4 cup (70 g)
15 lb (7 kg) 1 can + 1/4 cup (23 g) 1/2 cup (39 g) 5/8 cup (55 g)
17 lb (7.5 kg) 1 can + 1/4 cup (26 g) 1/2 cup (43 g) 3/4 cup (60 g)
18 lb (8 kg) 1 can + 3/8 cup (29 g) 1/2 cup (47 g) 3/4 cup (64 g)
19 lb (8.5 kg) 1 can + 3/8 cup (33 g) 5/8 cup (51 g) 3/4 cup (69 g)
Royal Canin Veterinary Diet Feline Urinary SO Loaf in Sauce Canned Cat Food

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Customer reviews

Jennifer77
24 Sep 2021

Unexpected change in can size.

Thanks. I hate it. If I had any choice I would never buy from you again. You are a predatory company. I hope you have the life you deserve.
LoriAnn27
13 Sep 2021

Stopped using the new UR canned food

Our cat was on the UR green cans for 8-10 years and did well. This winter our cat begin throwing up his food, losing weight, having very smelly poop, etc. I took him to the vet 3-4 times, we added the Royal Canin dry food to his diet, tried probiotics, tried prednisone; nothing helped. Thank goodness a few weeks ago, our vet was out of Royal Canin and I couldn’t find it anywhere so I began feeding him the vet Purina UR savory selects. No more throwing up, no smelly poop, and his fur is getting better. After all this and I check the reviews on this site and found out about the formula change….wished I would have questioned why the Royal Canin can changed colors…. Not ever buying food from this company again!
Sandraphc
05 Sep 2021

Seeking alternative brand due to smaller can size

I am looking into other brands due my displeasure of the (smaller can size/price). Bad idea all around (customer satisfaction, carbon footprint and environmental impact). I can’t find the magnesium content for the SO so that I can compare with Science Diet and Hill’s uninary products.
Peevedpuss
04 Sep 2021

Why, why, whyyyyyy would you change the can size?

I mean, we all know why... but it's so frustrating. I will pay more for an already expensive food because it is what my cat needs to stay alive, all of us here are a captive market. You have our business... but, come on, the ol' can size switcheroo is an such an insult. I would threaten to use another product or spend my money elsewhere, but you know as well as we do that there aren't other options. So I will continue to begrudgingly buy your product because I have to, because I want what's best for my cat, but the second I have a viable option, I'm out.
Hey Pook
31 Aug 2021

Add inconvenience to an already pricy product

12% small cans now for the same price. Our cat has been on this for many years and due to scaring in his throat (due to a horrible vet), we have to add 4 tablespoons of water to each 5.8oz can and mix it up so he can swallow it. What's 4 tablespoons minus 12%? PIA! If you need to bump your bottom line, just raise the already high price and stick it to us that need your product and don't mess with the portion size of the can for those of us who rely on it. If it were easy to find another product for our cat I would do it.
JohnL
30 Aug 2021

Horrible Decision

Our boys have been on the 5.8 royal canin urinary SO for years. The price has always been high but we tolerated the expense. The price went up over 15% in the past year, and now Royal Canin has reduced the size of the can by 12% without reducing the price. This increases my cost dramatically, and also causes a problem determining how much food to give each cat. Bring Back the 5.8 oz can please. I am looking at alternatives due to the changes the company has made in the product.
007NYC
28 Aug 2021

Well, you used to make a 5.8 oz can

How can you stop making the 5.8oz cans? It's SO NOT NICE to do to the people who need your food the most. I'm actively seeking other brands. You will NOT be getting my business anymore. Peddle your small cans to someone who can afford it.
MyCatRocky
25 Aug 2021

Great food,ridiculous size can

For years, this food has helped my cat Rocky. After suffering bladder stones and having an operation, the Vet put Rocky on this food exclusively. He loves it, which is great because it is the only thing he can eat to prevent problems. The can size has just been reduced from 5.8 oz. to 5.1. Seriously? Am I supposed to feed my cat less food? Now I am forced to do complex mathematics to make sure Rocky get the same amount of food that he had before. Please bring the 5.8 oz. cans back!
ChCo
12 Jun 2021

Did you changed for,USA? Why?

My cat has been on the same diet of Urinary SO for 9 yrs. Never had an issue. I have been wondering if it was a new formula for a while now. Recently for the past 2 mos my cat has been having diarrhea and loosing weight. He is a strictly indoor cat since he was 6 weeks old and he is now 10yrs. Nothing has changed in our house, no new food, etc. He has been to vets twice, once as an emergency due to diarrhea and lethargic. All the tests have come back negative. The only thing changed recently is a new shipment of the SO canned food. Did you change the formula and why? I see others have been having issues too. He still eats the food but is not having normal stools eve since started the last shipment. Please reply!
MinasMom
15 Mar 2021

Very disconcerting...

Our senior kitty has been on this food all her life as she is prone to urinary tract infections. Over the last year or so, we've noticed that our kitty has not been eating regularly or seems so famished that she goes through extra food. My husband and I have discussed whether there was something wrong with the food - maybe more or less water content or SOMETHING - and now I see that may actually be the case. We've even done additional bloodwork at the vet thinking something was wrong with her. As we have the food auto-shipped through Chewy, they recently advised that they will not be getting the food in the future. When I looked elsewhere - out of stock. Why did I have to come to this website to learn that the formula was changed and that other cats are struggling similarly. Have already contacted the vet to find an alternative. Not cool, Royal Canin. Not cool.