Royal Canin Veterinary Diet Adult Urinary SO Dry Cat Food, 7.7-lb bag

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About This Item

Details

  • This veterinary-exclusive dry cat food is specially formulated for adult cats with urinary health concerns.
  • Helps dissolve pure struvite stones and prevent calcium oxalate stones.
  • Uses RSS methodology for cat bladder health to help lower the risk of crystal formation.
  • Creates an environment unfavorable to crystal formation in the bladder.
  • Provides a specialized diet with a reduced level of magnesium to help prevent struvite stones from reoccurring.

Ingredient Information

Feeding Instructions

FAQ

Learn More About Royal Canin Veterinary Diet From Our Team of Experts

About Royal Canin Urinary Health for Cats

Royal Canin, incredible in every detail.  Tailored nutritional solutions for urinary health.

Worried About Your Cat’s Urinary Health?

Your veterinarian is the expert on your cat’s health, so you should always consult with this trusted advisor to find the best urinary health solutions for your pet. Royal Canin works closely with veterinarians to develop cat formulas that help support urinary tract and bladder health.

How Can Nutrition Help?

Your veterinarian may recommend a Royal Canin Urinary formula for your cat. These special formulations can:

Dilute Urine

This helps your cat urinate more often, which can help minimize time for stones to form.

Lower RSS

RSS methodology predicts urine crystallization and is used to develop diets that reduce the risk of stone formation.

Maintain Balance

A precise mineral balance can also help prevent stones from forming.

Set Up Autoship for Consistent Delivery

Last-minute dietary changes can sometimes upset your pet's stomach. Set your Royal Canin pet food order to Autoship to keep feeding on track and avoid unwanted disruptions.

About Royal Canin

What sets Royal Canin apart is their close collaboration with veterinarians. Through these professional partnerships, they strive to learn everything they can about pet health, including how different formulas perform for different breeds, sizes, lifestyles and therapeutic conditions. Ongoing research and development allows Royal Canin to keep providing the precise nutrition cats need for a range of medical conditions.

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Questions & Answers

26 Customer Questions


What does the SO stand for in the urinary SO?

Answer by ChewyFeb 11, 2019
SO stands for struvite oxalate.

Should the bag come vacuum sealed? I received the bag and it doesn't look vacuum sealed as it's got air in it. Can I still feed it to my cat??!

Answer by ChewyAug 06, 2019
Royal Canin's bags are not vacuum sealed, however are nitrogen flushed. During packaging, the oxygen is forced out of the bag to keep kibble fresh. Kibble is safe to feed as long as it's before the expiration date.

What is the magnesium, ash & phosphorus content?

Answer by ChewyOct 26, 2020
This variety contains approximately 0.1% Magnesium content on an as fed basis (0.1% on a dry matter basis), 1.26% Phosphorus content on an as fed basis (1.3% on a dry matter basis) and the 7.2% Ash content on an as fed basis (7.9% on a dry matter basis).

What is the size of the kibble? I have Maine Coons and they like large kibble.....

Answer by ChewyNov 19, 2019
The kibble for this formula is about half the size of a regular M&M.

4.7
Rated 4.7 out of 5 stars
8007 Ratings

Customers Mention

Chewy identifies key considerations with the help of artificial intelligence and our veterinarians.

Ease of Use

90% Positive

Effectiveness

90% Positive

Ingredients

91% Positive

Long-Term Benefits

92% Positive

4068 Customer Reviews



Always consult a veterinarian about your pet’s health needs. Customer reviews should not be used as medical advice.

Rated 5 out of 5 stars
By Robin on Jan 17, 2026

Excellent Customer Service

Too early to tell regarding the prescription item itself, but I wanted to comment about the excellent customer service I received. In regard to receiving this product,

Too early to tell regarding the prescription item itself, but I wanted to comment about the excellent customer service I received. In regard to receiving this product, I was informed it was going to be delayed. I called and expressed my dismay and concern. The representative, Lauren, who took my call was kind, understanding and knowledgeable. She took care of the issue, expressed her apologies on behalf of the company and took great care to make sure my issues were addressed and that I was pleased. I was so impressed and felt validated and valued. Thank you Chewy and Lauren for your quick action and care!


Rated 5 out of 5 stars
By Stacy on Dec 20, 2025

Loved it!

Got this for one of my (neutered) cats, Silver, brother to Mr. Ears, after he suddenly got a complete urinary blockage & was hospitalized. Told by my vet he had

Got this for one of my (neutered) cats, Silver, brother to Mr. Ears, after he suddenly got a complete urinary blockage & was hospitalized. Told by my vet he had to have this and only this food. Also purchased the wet canned Urinary SO. He loved this food and the wet version too! (Not sure why my review for the canned morsel Urinary SO wouldn't go through?) Unfortunately Silver developed another blockage within a few weeks and I couldn't afford another $800.+ veterinary stay so tragically and heartbreakingly had to have him euthanized. The hierarchy in our home has been dismantled ever since. Silver was everybody's snugglebud & everybody's playmate. He loved the urinary SO food though.


Rated 5 out of 5 stars
By Katie on Jan 8, 2026

Consistently my picky cat's FAVORITE

My cat had emergency treatment for urinary crystals many years ago. he went on Royal Canine SO canned food for seven years, no problems. Then, for no reason, he

My cat had emergency treatment for urinary crystals many years ago. he went on Royal Canine SO canned food for seven years, no problems. Then, for no reason, he decided he didn't like it anymore. We switched to many different brands with no luck, until finally we found a small canned food that he will eat. We decided to try the RC dry as a topper and That was the ticket! No more fussy cat as long as he gets his Royal Canin SO dry food along with it. Now he is getting the best of both worlds. Great stuff.


Rated 5 out of 5 stars
By Cydlee on Dec 30, 2025

No More Random Peeing

My cat, Betty, was great about using the litter box until....she wasn't. She began to pee in random places around the house. My vet discovered Betty had a build

My cat, Betty, was great about using the litter box until....she wasn't. She began to pee in random places around the house. My vet discovered Betty had a build up of crystals in her urine, causing pain and urgency. Poor thing! So the vet recommended switching Betty's food to Royal Canin S/O Diet, which was formulated to eliminate crystals in the urine. Betty has been on this diet for years now, and there have been no more accidents around the house. So grateful for this simple fix!


Rated 4 out of 5 stars
By TT on Dec 31, 2025

Effective diet, but a smaller bag option would be helpful

We have used Royal Canin Veterinary Diet Urinary SO for several cats over the years, and it has been very effective. Currently, only one of our cats requires this

We have used Royal Canin Veterinary Diet Urinary SO for several cats over the years, and it has been very effective. Currently, only one of our cats requires this diet. The 7.7 lb bag lasts over two months, even when stored in an airtight container, but it seems to lose freshness over time. We can clearly tell the difference when opening a new bag. I understand that smaller bags (around 3 lb) are available elsewhere, so I would really appreciate it if Chewy would consider offering a smaller size. I would be willing to pay a little more per pound for a fresher and more convenient option.


Rated 5 out of 5 stars
By Lee on Jan 14, 2026

It worked wonders!

My girl had crystals in her bladder and switching to this, in four weeks they are almost gone! Because we have multiple cats they all now eat the same kibbies. Everyone

My girl had crystals in her bladder and switching to this, in four weeks they are almost gone! Because we have multiple cats they all now eat the same kibbies. Everyone is doing very well. Since it has better ingredients than our store kibbies they actually eat less, look great and are very playful with each other. No more cat barf! Yahoo!


Rated 5 out of 5 stars
By Debra on Dec 20, 2025

VET RECOMMENDED

After an expensive visit to the vet, we found our fur baby had a stone and crystals in her bladder. The Vet sent us home with this expensive urinary diet to dissolve

After an expensive visit to the vet, we found our fur baby had a stone and crystals in her bladder. The Vet sent us home with this expensive urinary diet to dissolve the bladder stone and crystals. Upon her checkup the stone and crystals were dissolved. Now she will be eating this diet going forward so ordered the largest bag so both fur babies could eat her necessary diet. Has stopped her from spraying furniture as well.


Rated 5 out of 5 stars
By Paige on Jan 5, 2026

Helped our cat so much!

This food was prescribed by our vet after our cat, Tucker, had urinary blockages and we almost lost him. We are incredibly thankful that this food is out there and

This food was prescribed by our vet after our cat, Tucker, had urinary blockages and we almost lost him. We are incredibly thankful that this food is out there and all it did to restore our sweet boy back to good health! It is pricey, but 100% worth it that we’ve never had any issues with him blocking ever again.


Rated 5 out of 5 stars
By Diane on Jan 15, 2026

Helps my boy cat

Poor guy had major blockage, surgery and occasionally gets infected. Since eating this and sometimes matching wet food too, he’s been good. Other cats like it too

Poor guy had major blockage, surgery and occasionally gets infected. Since eating this and sometimes matching wet food too, he’s been good. Other cats like it too which I glad about. Worth the money. Methionine is very important for this problem, this food has it.


Rated 5 out of 5 stars
By B Kevin on Jan 16, 2026

Effectiveness

The purpose of switching to this was to make sure my Spencer kept himself hydrated so his kidneys would not fail before his normal lifetime. This food has completely

The purpose of switching to this was to make sure my Spencer kept himself hydrated so his kidneys would not fail before his normal lifetime. This food has completely motivated him to drink all the time after eating and throughout the day.