Formulated with low molecular weight peptides to support dermatological and gastrointestinal health in cats with food sensitivities.

Formula and production process aimed at excluding sources of food allergens.

Formulated to support the skin’s natural protective barrier for optimal skin health.

A synergistic complex of antioxidants to support cellular health.

Specially formulated to assist in the management of severe adverse food reactions in adult cats.

Working toward a sustainable future

Our belief that pets make our world better inspires and gives life to our purpose of making a better A BETTER WORLD FOR PETS ™

Discover more
Labrador Retriever adult sitting with its owner outdoors

Corn starch, hydrolyzed poultry by-products aggregate, coconut oil, vegetable oil, powdered cellulose, natural flavors, dried chicory root, fish oil, calcium sulfate, sodium silico aluminate, potassium chloride, fructooligosaccharides, sodium pyrophosphate, monocalcium phosphate, DL-methionine, choline chloride, L-lysine, vitamins [DL-alpha tocopherol acetate (source of vitamin E), L-ascorbyl-2-polyphosphate (source of vitamin C), niacin supplement, vitamin B12 supplement, D-calcium pantothenate, biotin, pyridoxine hydrochloride (vitamin B6), riboflavin supplement, thiamine mononitrate (vitamin B1), vitamin A acetate, folic acid, vitamin D3 supplement], taurine, L-tryptophan, L-alanine, histidine, salt, trace minerals [zinc proteinate, zinc oxide, manganese proteinate, ferrous sulfate, copper sulfate, manganous oxide, sodium selenite, copper proteinate], marigold extract (Tagetes erecta L.), rosemary extract, preserved with mixed tocopherols and citric acid, glycine, magnesium oxide, potassium iodate.

Calorie Content

This diet contains 3766 kilocalories of metabolizable energy (ME) per kilogram or 335 kilocalories ME per cup on an as fed basis (calculated).

Crude Protein (min) 24.5%
Crude Fat (min) 15.0%
Crude Fiber (max) 5.7%
Moisture (max)8.0%
Vitamin E (min)413IU/kg
Ascorbic acid* (min)160mg/kg.

*Not recognized as an essential nutrient by the AAFCO Cat Food Nutrient Profiles.

Weight of Cat Overweight Normal Lean
4.4 lb (2 kg) 1/4 cup (26 g) 3/8 cup (32 g) 1/2 cup (39 g)
5.5 lb (2.5 kg) 3/8 cup (30 g) 3/8 cup (38 g) 1/2 cup (46 g)
6.6 lb (3 kg) 3/8 cup (35 g) 1/2 cup (43 g) 5/8 cup (52 g)
7.7 lb (3.5 kg) 1/2 cup (39 g) 1/2 cup (48 g) 5/8 cup (58 g)
8.8 lb (4 kg) 1/2 cup (42 g) 5/8 cup (53 g) 3/4 cup (64 g)
9.9 lb (4.5 kg) 1/2 cup (46 g) 5/8 cup (58 g) 3/4 cup (69 g)
11.0 lb (5 kg) 5/8 cup (50 g) 3/4 cup (62 g) 7/8 cup (75 g)
12.0 lb (5.5 kg) 5/8 cup (53 g) 3/4 cup (67 g) 7/8 cup (80 g)
13.2 lb (6 kg) 5/8 cup (57 g) 3/4 cup (71 g) 1 cup (85 g)
15.4 lb (7 kg) 3/4 cup (63 g) 7/8 cup (79 g) 1 1/8 cups (95 g)
17.6 lb (8 kg) 3/4 cup (69 g) 1 cup (87 g) 1 1/8 cups (104 g)
18.7 lb (8.5 kg) 7/8 cup (73 g) 1 cups (91 g) 1 1/4 cups (109 g)
Royal Canin Veterinary Diet Feline Anallergenic Dry Cat Food

Still have questions about this product?

Find out how to reach us, and get in touch

Ask a question

Customer reviews

27 Jan 2024

Finally a food for my kitty with a very sensitive

My adopted feral kitty had horrible stomach issues and her stomach bloated/swelled and the litter box stunk like you can't even imagine, or she was allergic to everything - and where her ears would itch and she would scratch constantly. After trying six different prescription foods this is the first one that worked!!
11 Jan 2024


Vet prescribed this food as we suspect food allergies. Upon opening the bag I almost gagged at the smell. Pretty sure my cat thought the same, as he didn't want to eat it the first week. (he usually devours his food) He eventually would eat it. Also, pretty sure this food made my cat vomit bile. Noticed the 1st ingredient is corn starch, that's odd since even the cheap food usually have some sort of meat first. The 2nd ingredient is poulty by-product..chicken is one of the most common allergens in cats why is this in allergenic food. Waste of money.
13 Oct 2022

What happened?

I've been buying this product since my cat was diagnosed with having a thyroid disorder. I haven't been concerned with the price even though I have notice an increase with both this product and the hydrolyzed protein. However, this is the only food that my cat will eat without it making him severely sick. Lately, this product has not been sold in stores, not even on chewy. What exactly is the issue, is the ingredients? I do not understand how this product just stops being stocked in stores, when it does become available it's gone before anyone gets a chance to purchase.
Linda W
17 Dec 2021

primary ingredient is corn starch

First ingredient is corn starch, 2nd ingredient is hydrolyzed poultry by-products aggregate. No other "meat" is listed. It has an unattractive odor and hasn't helped with my cat's constant vomiting for which it was prescribed. He eats it reluctantly. I think it is overpriced for the lack of results and lack of protein. Protein content is listed as a minimal 24.5%.
Royal Canin response
Thank you for your feedback and for questions about the ingredients please reach out to our Consumer Care team at 800-592-6687
19 Oct 2021

What changed?

I've been feeding my cats a combo of Ultamino and Hydrolized Protein for four years (except for several times when it was out of stock). This was prescribed by vet soon after cat adoption from shelter to cope with sensitive tummies. But for the last month, they both vomit several times a week -- undigested food soon after morning feeding. They don't seem to be sick or uncomfortable. And they enjoy and tolerate their evening feeding of canned food. Did something change in the formula?
09 Jun 2021

Works I guess??

My cat gets urinary crystals, so I had to switch her to a prescription diet for that almost a year ago. She immediately threw up the royal canin SO food, so I switched to purina for a little while, until she developed skin allergies to that and refused to eat. After trying some others (science diet, rc urinary+hydrolyzied) she was still having allergic reactions and throwing up. I’ve had this for a few weeks and she still refuses to eat it on her own. I have to give her individual pieces like I’m giving her a treat, and even then she’ll only eat maybe a tablespoon at a time. She hasn’t been throwing up or having worsening skin allergies, but whether it’s the smell or the HUGE pieces, she will not eat this like food. I wish there was a wet food version that I could try because she might actually eat that, but hopefully my vet and I will be able to find a food she’ll eat and not be allergic to soon.
07 Jun 2021

Inconsistent quality

This food has been a life saver for my cat with food sensitivities/protein allergies. However I find that the quality of food varies from batch to batch. Some bags I purchase are great, and sometimes I buy a new bag of food, and my cat reacts to it right away (gets itchy, moody, stool changes, she is obviously in pain). It's like there is no quality control at RC whatsoever. Getting seriously tired of this....
21 Mar 2021

Only food she can eat. She likes it. Wet version??

My kitty has IBD and eventually kept developing allergies to everything I tried to give her over time. Novel proteins, raw diet, you name it. I was using the Hills Z/D before because I REALLY didn't want to give her a kibble diet (especially bc she is prone to urinary issues), but she eventually started reacting to even that over time. She improved noticeably when I switched her to Ultamino. Unfortunately it's still not enough - she started having problems again after a year on this and is now on steroids and chemo (chlorambucil) for early stage small cell lymphoma and IBD. But the vets say this is the most hypoallergenic option, so I am glad it exists at least. However, I REALLY wish they would make a hypoallergenic pill pocket! SO many of us who need to use this RX food end up needing to medicate our purrbabies, and it would make life so much easier for them and us if there was a way to pill them with a pill pocket or even wet food. Please PLEASE work on developing a hypoallergenic wet food or pill pocket, or both! One last note - I really appreciate that I can just call and speak with a nutritionist at RC when I have questions. It was them more than my own vet that impressed upon me the importance of eliminating all other potential sources of allergens in her diet. I assumed it was OK to occasionally give other treats that as far as I knew didn't bother her system, but I didn't fully understand how allergies develop and wasn't warned enough by the vets that she could develop allergies to even the most hypoallergenic food if given a non-hypoallergenic treat occasionally that would make her body associate them. I wish I'd known sooner, but I'm glad I at least found out, thanks to a RC nutritionist.
Holly Fazio
24 Feb 2021

Did the formula change?

My cat has allergies and stomach ulcers. She's been on Ultamino for about four years now but with the latest bag with the new packaging, she's been throwing it up. Has the ingredients/formula changed? Not sure if I should just give her more time to acclimate or change brands.
17 Nov 2020

Keeps my cat's tummy issues at bay

My cat has tummy issues, we think it's a parasite, but just in case we give her this food plus probiotics. Just wish there was a treat or wet food option so she doesn't get bored so easily! Also this food has the distinct smell of tomato soup, but I wouldn't call it a bad smell especially because cat food normally smells much worse! Also it's super expensive, but what can ya do about that?