Royal Canin Veterinary Diet® Feline Urinary SO® dry cat food

Founded by a veterinarian, Royal Canin has over 40 years experience in health nutrition. Our work with pet nutritionists, breeders, and veterinarians from around the world has provided us with knowledge about the specific nutritional requirements of cats. This knowledge has allowed us to formulate the optimal diet for your cat's special needs.

  • Supports Struvite Dissolution
  • Increases urine volume to help decrease struvite and calcium oxalate levels
  • Supports urinary health
  • Reduced magnesium level
  • Royal Canin Urinary SO Index® promotes a urinary environment unfavorable to the development of both struvite and calcium oxalate crystals
  • 100% Complete and Balanced Nutrition
  • 100% Satisfaction Guaranteed

Feline Urinary SO is formulated to meet the nutritional levels established by the AAFCO Cat Food Nutrient Profiles for maintenance.

Where to Buy
Size: 17.6 lb
Size: 7.7 lb
Product Information

Struvite Dissolution
Provides nutrition that aids in the management of pure struvite uroliths.

Urine Dilution
Increasing the urine volume simultaneously reduces the saturation of urine with calcium oxalate and struvite crystals.

Relative Super Saturation (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.

Controlled Magnesium
Reduced level of magnesium, a natural component of struvite stones.

Feeding Guide
Recommended Daily Feeding Portion
Weight Low Activity Medium Activity High Activity
3.3 lb (1 1/2 kg) 1/4 cup (21 g) 3/8 cup (27 g) 3/8 cup (32 g)
4.4 lb (2 kg) 3/8 cup (26 g) 3/8 cup (33 g) 1/2 cup (40 g)
5.5 lb (2 1/2 kg) 3/8 cup (31 g) 1/2 cup (39 g) 5/8 cup (46 g)
6.6 lb (3 kg) 3/8 cup (35 g) 1/2 cup (44 g) 5/8 cup (53 g)
7.7 lb (3 1/2 kg) 1/2 cup (39 g) 5/8 cup (49 g) 3/4 cup (59 g)
8.8 lb (4 kg) 1/2 cup (43 g) 5/8 cup (54 g) 3/4 cup (65 g)
9.9 lb (4 1/2 kg) 5/8 cup (47 g) 3/4 cup (59 g) 7/8 cup (70 g)
11.0 lb (5 kg) 5/8 cup (51 g) 3/4 cup (63 g) 7/8 cup (76 g)
12.1 lb (5 1/2 kg) 5/8 cup (54 g) 7/8 cup (68 g) 1 cup (81 g)
13.2 lb (6 kg) 3/4 cup (58 g) 7/8 cup (72 g) 1 cup (86 g)
14.3 lb (6 1/2 kg) 3/4 cup (61 g) 7/8 cup (76 g) 1 1/8 cup (91 g)
15.4 lb (7 kg) 3/4 cup (64 g) 1 cup (80 g)  
16.5 lb (7 1/2 kg) 7/8 cup (67 g) 1 cup (84 g)  
17.6 lb (8 kg) 7/8 cup (71 g) 1 1/8 cup (88 g)  
18.7 lb (8 1/2 kg) 7/8 cup (74 g) 1 1/8 cup (92 g)  
19.8 lb (9 kg) 1 cup (77 g) 1 1/8 cup (96 g)  
20.9 lb (9 1/2 kg) 1 cup (80 g) 1 1/4 cup (100 g)  
22.0 lb (10 kg) 1 cup (83 g) 1 1/4 cup (103 g)  
1 cup = 8 fluid ounces = 85 grams

Chicken by-product meal, brewers rice, corn gluten meal, corn, chicken fat, natural flavors, powdered cellulose, soy protein isolate, salt, grain distillers dried yeast, egg product, potassium chloride, fish oil, calcium sulfate, sodium bisulfate, vegetable oil, taurine, choline chloride, DL-methionine, 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], trace minerals [zinc proteinate, zinc oxide, ferrous sulfate, manganese proteinate, manganous oxide, copper sulfate, calcium iodate, copper proteinate, sodium selenite], marigold extract (Tagetes erecta L,), rosemary extract, preserved with mixed tocopherols and citric acid.

Guaranteed Analysis
Crude Protein (min) 32.5%
Crude Fat (min) 13.5%
Crude Fiber (max) 4.5%
Moisture (max) 9.5%
Magnesium (max) 0.08%
Calorie Content
This diet contains 3631 kilocalories of metabolizable energy (ME) per kilogram or 298 kilocalories ME per cup on an as fed basis (calculated).
Product Reviews
Royal Canin Veterinary Diet ® Feline Urinary SO ® dry cat food is rated 4.8 out of 5 by 1287.
Rated 5 out of 5 by from Works great and my cats love it! As the founder/administrator of a cat rescue, I have a large cat household. One of my cats has cystitis and used to get kidney stones on a regular basis. Even after a 3wk antibiotic treatment, he'd start peeing blood within 1 week after eating regular dry food again so I had to put all the cats on the S/O diet for their dry food. He hasn't had ONE issue with stones or bloody urine since we changed over. All my other cats love it as well and the bowls are empty every morning. On a side note, as a rescue, Royal Canin is my "go to" brand whenever one of our foster cats needs extra help like young weaning kittens or cats with health issues. I recommend it to everyone.
Date published: 2016-05-09
Rated 5 out of 5 by from excellent product Had first used another urinary vet diet. While it kept the crystals away, I didn't like the way it smelled after it was opened; even with a smaller bag that was open a shorter time. Researched and found Royal Canin S/O was available; also liked that it had more omega. My cat liked it; his coat got better and softer. Has been on it for years and doing great. Adopted another cat without the urinary problem. Once he got a taste of the S/O, he didn't want any more of the canned food I was feeding him per the adopting organization. So, I just put him on it as well to prevent a mix-up in foods. Another plus, I can buy the biggest bags and the food still smells good right to the bottom of the bag.
Date published: 2015-09-02
Rated 5 out of 5 by from my cats love it! I went to the vet with one of my two cats for a concern. My cat was urinating blood due to a high intake of calcium from the water supply and store bought food like friskies. The vet had me switch to urinary cat s\o. After a little under 1 week she was all better. Not only that but I had an overweight mane coon female cat that is very picky about her food. So i fed her the same food, and she now refuses to eat anything else. I tried some samples I received from a co couple of pet stores and no go at all. She literally went on a hunger strike. So much for saving $ on food. All in all the food is great, but I wish they would send out coupons cause man it is sure expensive.
Date published: 2015-08-10
Rated 5 out of 5 by from Keeping his urinary tract problem in check We have been feeding this product to Prince (Male neutered cat), after his near death experience, having a urinary tract infection and was rushed to the VET for a very expensive operation. He had an old man, who loved his company sponsor the expense and he is now doing great. Mostly outdoors but when he feels like it he comes in and owns the furnished basement. Loves his mice and rabbits! He lives on a nice acerage of farm/garden/lawn land and reports to us only when hungry or the snow is too deep! or he feels like being sociable. Black shorthair beautiful cat; could be out of the jungle book representing the black panther.....Baghira.
Date published: 2016-05-27
Rated 5 out of 5 by from Our heathy cats thank you! We feed our 2 cats the vet prescribed Royal We feed our 2 cats Royal Canin dry SO daily and use the canned version to supplement if we run out of dry food between purchases. We are very happy with the results! Our cat with the urinary problem has not been sick at all since starting this food. Both cats have a very healthy coat of fur and are mostly left alone when it comes to parasites. We live in a wooded area and expected to deal with fleas and tics. It has not been a problem even without the monthly meds. The food makes all the difference! We are thankful for Royal Canin and the research they have done to perfect their products.
Date published: 2018-10-02
Rated 5 out of 5 by from Not only healthy but tasty My cats Stormy and Keegan love this food. They get a small bowl twice a day after they eat the Royal Canin SO wet food, twice a day. I have to put Keegan's food away if he does not finish or Stormy will finish it for him... That's how much he loves it. Stormy eats all his food so I never need to put his away. I love that this food is not only nourishing them but its also something they truly love and enjoy. But, what I love most and am so grateful for is that your products are helping to keep my fur babies alive by preventing anymore kidney issues. Thank you very much for making products that help protect these members of our family. Royal Canin gets two thumbs up from me and 2 paws up from Stormy and Keegan:)
Date published: 2015-09-02
Rated 5 out of 5 by from Vet recommended When the second cat ended up at the hospital with urinary issues in less that a year it was time to switch them all to the Urinary SO. That was over two years ago and we've only had well visits ever since. I have 4 cats inside and it saves money in the long run to feed the Urinary SO. My Mom's cats started having problems so she switched hers to the same food too. They're not having problems anymore.
Date published: 2015-08-16
Rated 5 out of 5 by from Our cat's health and life have been saved. After one of our cats died due to a urinary tract blockage, we immediately began using the SO diet when another kitty developed crystals in his urine. We have had excellent results with this food and now have 3 male cats on this diet. We believe that this food has actually saved our cat's urinary tract health and possible his life, because he had 2 episodes of crystals before we put him on the Royal Canin SO. Since starting on this food several years ago, he's not had to return to the vet for anything other than his annual exams. Thank you Royal Canin! I don't ever want to lose another of our beloved cats to a blockage again.
Date published: 2016-05-09
Rated 5 out of 5 by from Definitely solve the problem My cat squiggles was diagnosed with struvite crystals in his urine. He was so blocked he urinated blood. We took him to the emergency vet clinic at which point the doctor advised us to place him on urinary so dry cat food. Within a couple of weeks we noticed him drinking more water and urinating in his box without pain or discomfort. This is a terrific food and he has been on it for a few years now. He is doing terrific, drinking lots of water. We did try to switch him back to his old cat food, resulting in struvite crystals again. Lesson learned he will remain on this cat food for life.
Date published: 2018-04-06
Rated 5 out of 5 by from Delicious AND Nutritious!!! I first used Urinary SO when one of my male cats had a urinary blockage, and it was prescribed by my vet. Some time later, another of my cats had a similar medical problem, and again this food was prescribed. I asked my vet if feeding this food on a regular basis would be ok, and could help in preventing these types of issues, and she said absolutely. I have fed this to my cats ever since. I have 3 male cats, and they all love the food and none of them have had any type of urinary issues since this had been the main staple of their diet. LOVE how happy and healthy my boys are!!
Date published: 2017-05-02
Rated 5 out of 5 by from trusted to avoid bladder stones My four year old male cat suffered a single bladder stone that grew to nearly the full size of his bladder before we successfully diagnosed it (because palpation didn't effectively reveal a single stone, as usually two or more are rubbing together). After his surgery, the vet recommended feline urinary health SO to avoid the redevelopment of bladder stones. I'm pleased to say my boy eats it with no fuss. And since both our cats are self-feeders, his sibling eats it as well. Neither has experienced unhealthy weight gain, and their energy and appetite remains very good after two years. We are grateful for this product!
Date published: 2016-05-29
Rated 4 out of 5 by from No More Blocks I have two cats that have had urinary issues. One was on Science Diet C/D and continued to have issues (this was five+ years ago). But as soon as I switched him to RC Urinary SO, he's been totally fine. The second cat has had two blockages. He was on this food while he developed the second blockage. But we found out he'd been stealing regular food from another of our cats. As soon as we started locking him up at feeding time, he's been fine. My only complaint is that it seems bag to bag, the flavor must change. Some bags my picky cat gobbles it up. Then the next bag, it'll be really hard to get him to eat it.
Date published: 2018-11-01
Rated 5 out of 5 by from Best Cat Food Around I use the Feline Urinary SO. I have 4 cats, my vet put the one male on this food many years ago and we have never been back to the vet for a urinary tract infection. After a month of him being on this food and trying to separate him from the others as they wanted what he was eating. So I started feeding all my cats this food. It was the best decision to switch everyone over.
Date published: 2015-08-28
Rated 4 out of 5 by from Did it’s job About 2 years ago my MN DLH got blocked and after hundreds of dollars later my doctor told me I should place my baby on RC SO, since I am a technician I know the importance of a good quality food. I can honestly say since having my babies on SO there has not been any urinary problems since. I tell all my urinary problem patients to use y’all. My cats love the taste ( they turned their nose up to Hills C/D) but I have noticed a change in their weights both lost a lot of weight (both were NOT overweight to begin with)and a huge change in their water intake which I would say is the only downside to this great product
Date published: 2018-10-03
Rated 5 out of 5 by from Great food I bought this food when my kitties had a problem . All three love this food . I am so glad our vet told us about it !
Date published: 2016-05-27
Rated 4 out of 5 by from Seems to be working My cat had urinary tract crystals and had to be put on a special diet. My Vet recommended Royal Canin S/O. Pros: Works, Sid seems to like the taste. Cons: Ingredients... Soy protein doesn't seem like what cats eat? Price is high. My cat never seems full. I add extra water so he'll urinate more and if he doesn't eat it all, he won't touch it. Seems like a lot is wasted. If your cat has urinary tract problems, I would recommend. I wish there was something cheaper that the Vet thought would work. Until then I'll continue buying Royal Canin S/O. It has been working.
Date published: 2015-08-10
Rated 5 out of 5 by from Does What It Says It Will My 12 year old feline (with allergies) was diagnosed with bladder stones 2 years, had surgery for removal. My vet recommended RC Urinary SO for her diet. I have had Lilly on this formula for two years. At her recent checkup, she had an abdominal Xray to rule out possible stone recurrence, but her bladder was free from stones, her blood work was great, and she loves the taste. Thanks for a terrific product--she is on RC Urinary SO for life!
Date published: 2015-08-11
Rated 5 out of 5 by from good product Royal canin is a great product and my cats love the taste. Their coats stay Shiney and healthy looking. I have 5 rescue cats, 3 of them have to be on the prescription urinary so. It is such a great product that I feed it to all my cats. They all love it. I have tried other prescription brands in the past but was very unhappy with the quality of their products and my cats coats looked terrible on those products. I am very happy with the quality of the royal canin product and will continue to feed it for years to come. I also feed the urinary so canned food as well.
Date published: 2015-08-28
Rated 5 out of 5 by from Royal Canin saved my cat’s life! My 6 year old, 20 pound, Garfield was having blockages in his bladder shortly after my husband and I welcomed our first child. We had just moved, and I was so far away from his regular Veterinarian. Nervous to try a new Vet, I took him in expecting the worst. He had had several blockages before, and I just knew we were going down that road again ($$$). The Vet suggested I switch his food to the Royal Canin SO as it helps cats with blockages. She was right! It started working right away! I will always share my story of how a simple food change saved my cat’s life, in hopes to help someone else! LOVE ROYAL CANIN!
Date published: 2018-10-02
Rated 5 out of 5 by from Vet Recommended For a Reason! My cat started urinating outside of his cat box which was so unlike him. Upon further notice the poor guy was urinating blood. I was so worried that that he was not going to make it. I took him to the vet and she recommended Royal Canin Veterinary Feline Urinary cat food and within a week my cat was back to normal! Thank you Royal Canin!
Date published: 2015-09-03
Rated 4 out of 5 by from My Cats Really Like the Food. I originally bought this product because one of my cats had a urinary blockage and the vet recommended it. All 4 of my cats eat it, and seem to really enjoy the taste. They can't wait for meal time. The only issue I have with it, is that it seems to cause some weight gain and in one of my cats in particular. We have switched to the moderate calorie and that seems to help a little. I also wish that it was more natural with less filler in it. I feed only natural food products to my pets typically, items with higher real meat and vegetables in it. I don't have a choice with this product if I want my cat to continue to stay healthy, but I do feel it could be made more organic and natural for the overall well being of cats eating it.
Date published: 2016-06-05
Rated 5 out of 5 by from Excellent and tasty cat food! I have been buying this formula for my cat that had struvite stones and almost died! We were worried that he would get blocked again but its been almost 2 years on this formula and he hasn't had any more stones!! Also every cat in my household loves the flavor, its hard to give it to just my one cat without the others trying to eat it too! Now my cat is happy and healthy, just look at his picture!
Date published: 2015-08-11
Rated 5 out of 5 by from My cat loves it! We started using this food after our cat, Duncan, nearly died from a blocked urinary tract. Although the vet had recommended the special diet, we didn't start using at first, but a relapse convinced us. He has not had another incident since being on the Royal Canine diet!
Date published: 2015-08-10
Rated 1 out of 5 by from Causes vomiting!!!!! My cat has been using urinary so for about a year, and in the past few months he was throwing up frequently. I read other reviews about other cats experiencing vomiting due to this cat food so I switched his food. Since I have switched his food his vomiting has stopped. While this cat food resolved my cats urinary problems, it caused vomiting so I would not recommend this product.
Date published: 2017-07-01
Rated 4 out of 5 by from Has Kept My Louie Healthy! My male Maine Coon, Louie, has been on this diet for years. He has a tendency to develop urinary tract crystals and this diet has kept him healthy and out of the vets office since he was about 4 years old. He is now 11. He eats it well, both the dry and the canned but I feed the dry the most because he seems to like dry food the best, maybe it's the crunch? I'm just glad it works because he plugged up on me when he was about 4 and I almost lost him. Thank you Royal Canin, for allowing me all these years with my baby! I look forward to many more.
Date published: 2015-08-10
Rated 5 out of 5 by from Excellent! Saved our cats life! This food is amazing! We almost lost 2 of our male cats due to blockage. After medical care and unblocking both cats have been put on this diet only. It has saved their lives! We are so very thankful!!
Date published: 2015-08-10
Rated 5 out of 5 by from Great product! I have been buying this urinary SO for many years now for all of my Manx cats, it truly is a lifesaver for my cats. Thanks Royal Canin
Date published: 2015-08-11
Rated 5 out of 5 by from I so appreciate this product. I found ferrel cat or perhaps he found me. Benjamin is the sweetest most docile animal. One day I kept finding him in the bathroom. Later that evening I found him in the bathtub. There was blood all over the tub and he was lying in there very sick. I took him to the emergency vet and found out he was unable to urinate due to crystals that develop in his urethra. After several days my vet recommended this food. Benji has had no symptoms of this problem now for almost a year. He's happy and likes the food a lot. Thank you for developing this product to treat animals with this condition. You have extended his life and so far we have avoided a costly and painful surgery. Thank you from both of us. Melissa and Benji
Date published: 2016-05-31
Rated 5 out of 5 by from My cats think it's kitty treats -- When my vet first gave me a sample of Urinary SO to take home -- BEAUTIFULLY packaged in a paw print goody bag with matching ribbon -- my cat TORE through the bag to get to the food. (He had rejected some other brands before we landed this one.) Only one of my three rescues, Possum, really needed to have this food after a urinary issue. However the other two, Priscilla and Ceilidh, have since refused to eat their "normal" food and go after the Royal Canin. Needless to say, there are no urinary tract issues in this house for any cat!!!
Date published: 2015-08-10
Rated 5 out of 5 by from Best Urinary Formula Ever! This is hands down a winning formula. My "Farfel" kitty has been right as rain since we got him onto this formula. He was having chronic occurrences of Oxalate Bladder stones with no success on other brands. Thankfully since going on Urinary SO, he has been oxalate and pain free for 21/2 yrs now and he love's this formula! It has a very appealing aroma from my perspective as well as my kitties and it WORKS! Bravo Royal Canin !
Date published: 2015-08-21
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