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

Gine
08 Feb 2023

Royal Canin SO for dogs

I am so disappointed in this food. My dog has been on this diet for some time. It was a bit more expensive but saved us vet bills and it was worth it to avoid some issues she had in the past. However I agree with the other reviews. The cans are smaller, there is not doubt that the product itself has changed and the price has skyrocketed I t eh last few months. We payed 56$ not that long ago for 12 cans and now pay 77$. Unfortunately I don’t think we will be able to continue with this food. I feel that they are totally taking advantage of their customers. Shame on you! We will be looking into an alternative diet for our dear pet who clearly you do not care about.
Royal Canin response
Please know that the decision to increase our prices is never taken lightly, but it is necessary to continue to deliver a quality product for the pets that we serve. Our price increase was a singular occurrence at the beginning of the year. The rising costs of innovation, raw materials, packaging and transportation are reflected in the current price increase. I sincerely apologize for the frustration.
LouieB
31 May 2022

Too expensive for small 5.1 oz can that was 5.5 oz

My cat is young and needs urinary help but can has gotten smaller and now just went up in price all in the last year. I know some things are more expensive but instead of two cans a day my cat now needs three of small 5.1 oz. It’s too much to make 3 changes in a years time.
Bob999
26 May 2022

Royal Canin, very disappointed in them.

I’ve been buying royal canon products from my cats for many many years. I noticed a while back how their 6 ounce cans were actually 5.5 ounces. Now to my horror I see they reduce them to 5.1 ounce and still keep the same price. Instead of being honest and just raising the price they quietly make the cans smaller. Did the vet tell us to make their portion sizes smaller?
Lisa Mills
29 Mar 2022

First the company stopped making the treats and now all of a sudden my car won’t eat the last eat batch of wet food we received. Previous to this batch it was her favorite thing. Now won’t even take a bite. There must have been a change in this product as she is eating other things but won’t touch this suddenly.
Munchie
24 Mar 2022

New customer, works for us

My 2yr old male cat was having urinary blockage, requiring a couple vet visits. We were reducing dry food, trying to encourage more water, and leaning away from seafood, but by the second visit he required expensive surgery. Then we relented and tried this. Haven't had any issues since. The kicker is, although he is a bit finicky about food, he likes this canned stuff. I had already been mixing some water into his meat, not only to get him more, but because he eats kind of weird; he licks it into his mouth rather than biting into it. So even though this 'loaf' does appear a bit dry (still says "in Sauce" here, that's not right), we were already used to mixing in water to get it to a more goop like consistency. I guess it's expensive, but if it avoids the health issues from now on, I consider it worth it.
Jan4
15 Mar 2022

No sauce - dry and dense

I too am having issues with my cat not eating the food with less sauce/gel in the pate. It is dense and very dry. I have purchased 3 different lots and the same result. I did just contact customer care and explained the problem and provided the lot numbers and BBDates. They stated there has been no change - but you can clearly see it when you open the can. My cat will not eat it after 10+ years of eating it. I have been able to find a few lots just recently with the same amount of sauce/gel as previously - but not anymore. I do not want to have to go through changing my cat's brand but I may have no choice :(
kkohio
08 Feb 2022

Disappointed in downgrade

Very disappointed in Royal Canin for decreasing the size and charging the same price. I would prefer if they would have kept the same size and amount of gravy and charge the price that they need. My cat has not been eating the food with less gravy/sauce in it. I’m very disappointed in the Urinary SO 7oz. cans size being downsized to 5.1 oz. and the price is the same price. I would have preferred they just charge more to keep the original size and provide the same amount of gravy or sauce as before. Now I open a can and the cat will eat it a little of it once and then will not eat any more until I open a new can the next day. I would prefer now if they would sell the Urinary SO loaf brand in the smaller 3 oz cans. At least not as much would go to waste. Now Looking into Hills Science brands as a replacement.
Bora
16 Nov 2021

Bad pricing and can sizes

The only positive thing about this product and company is its quality. That's about it. This last year, they have had increased their prices which were already high as they reduced can size (twice). I don't mind the higher price for bigger cans, but going with a smaller can was a total rip-off and unacceptable. They certainly don't care about their customers and environment since they have preferred to go with smaller cans. Poor decision from a well-known brand. This is a perfect way to lose your customers' trust and your companies reputation.
Kate38
04 Nov 2021

Another vomiting cat

Another family with two cats who were longtime eaters of RC USO loaf and dry. When the formula changed, Chewy sent morsels because loaf was out of stock. One cat wouldn't touch them. The other hoovered them up and, within days, was vomiting multiple times a day. He was smacking his lips due to the nausea and lost his voice. We managed to get some loaf, but it was the newer loaf, and it also made him vomit. Finally zeroed in on the food after vet tests came back clear and the female cat had some loaf and vomited, too. Both cats are being switched to Hill's c/d. Cannot fathom a cat food company so disinterested in the health of cats or maintaining customers.
Slm28269
04 Oct 2021

Very disappointed in smaller can / higher price

This is a prime example of a company taking advantage of customers that have limited choices on food to keep their cats healthy. I will be actively researching alternative urinary foods to switch brands. Bait and switch - I hope karma comes back to this company!