What's actually in Royal Canin Maine Coon?
We analyzed Royal Canin Maine Coon Adult Dry Cat Food. The first five ingredients are chicken by-product meal, brewers rice, chicken fat, corn, and corn gluten meal.
Chicken by-product meal as the first ingredient is a significant downgrade from whole chicken or chicken meal. By-product meal is made from parts like necks, feet, intestines, and undeveloped eggs — it's a concentrated protein source, but a low-quality one. It's cheaper to produce and less digestible than named muscle meat or standard chicken meal. For a breed-specific formula that commands a premium price, leading with by-product meal is a tough look.
Brewers rice is a milled rice fragment left over from the beer brewing process. It's essentially the broken bits that weren't good enough for human food. Chicken fat at number three is a solid, named animal fat that provides essential fatty acids — one of the better ingredients in this formula. But then corn and corn gluten meal appear back to back, making corn the dominant carbohydrate source when you combine both entries. Corn gluten meal is a plant protein concentrator that inflates the total protein number without providing the complete amino acid profile cats need as obligate carnivores. Shop on Amazon →
The good stuff
The glucosamine and chondroitin sulfate inclusions are the headline here, and they matter. Maine Coons are the largest domestic cat breed, regularly reaching 15-25 pounds, and they're genetically predisposed to hip dysplasia. Joint support isn't a nice-to-have for this breed — it's a real nutritional need. Most standard cat foods don't include these supplements at all, so Royal Canin gets credit for formulating with the breed's specific health risks in mind.
Psyllium seed husk is a smart inclusion for a long-haired breed. Maine Coons have thick, semi-long coats that shed heavily, and hairball management is a genuine concern. Psyllium is a soluble fiber that helps move ingested hair through the digestive tract rather than letting it accumulate into hairballs. It's a more targeted approach than the generic "hairball control" fibers in most cat foods.
Green tea extract provides natural polyphenol antioxidants that support cellular health and immune function. Fish oil delivers marine-sourced EPA and DHA omega-3 fatty acids — the forms cats actually need, since they can't efficiently convert plant-based ALA. L-carnitine supports fat metabolism and healthy weight management, relevant for a large breed that can be prone to weight gain. Taurine is an essential amino acid for cats that supports heart and eye health — every cat food should include it, and Royal Canin does.
The not-so-good stuff
The by-product meal issue goes beyond just being the first ingredient. Chicken by-product meal is a vaguely defined category that can include a wide range of parts, and the quality varies significantly between batches. For an obligate carnivore, the protein source matters — and this one is bottom-tier among animal proteins.
The double-rice problem: brewers rice at number two and brown rice further down the list. When a formula includes two separate rice entries, it's a sign that rice is a bigger part of the recipe than any single listing suggests. Brewers rice in particular is a low-quality filler with minimal nutritional value beyond cheap calories.
The double-corn problem is worse. Corn at number four and corn gluten meal at number five means corn derivatives dominate the carbohydrate and plant protein content. If you combined them into a single "corn" entry, it would likely rank as the first or second ingredient by weight. Corn gluten meal specifically is a plant protein booster — it inflates the guaranteed analysis protein percentage without delivering the amino acid profile an obligate carnivore needs.
Wheat gluten is another plant protein concentrator. Between corn gluten meal and wheat gluten, this formula relies heavily on plant-derived protein to hit its numbers. Three separate gluten/plant protein sources in one cat food is aggressive padding.
Rice hulls are the outer shells of rice grains — essentially agricultural waste used as an inexpensive fiber source. They add bulk to the food without meaningful nutrition. Pea fiber serves a similar purpose as a cheap bulking agent. Neither ingredient has any business in a premium-priced, breed-specific formula.
How it compares
Royal Canin Maine Coon (C/58) scores 13 points higher than the generic Royal Canin cat food (D/45). The breed-specific joint supplements, psyllium seed husk, and green tea extract account for that gap — the base formula is similar, but the functional additions earn meaningful points.
Against Blue Buffalo (B/76), Royal Canin Maine Coon still trails by 18 points. Blue Buffalo leads with deboned chicken and chicken meal — two named animal proteins before any carbohydrate — and uses quality whole grains (brown rice, barley, oatmeal) instead of corn, wheat, and by-product meal. The breed-specific supplements are nice, but they can't close a gap that wide in base ingredient quality.
Read the full breakdown in our head-to-head comparison: Royal Canin Maine Coon vs Blue Buffalo.
For better alternatives tailored to Maine Coon HCM risk, joint support, and the breed’s extended growth window, see our full best cat food for Maine Coons guide.
The bottom line
Royal Canin Maine Coon Adult earns a C grade (58/100) from KibbleIQ. The breed-specific formulation isn't just marketing — glucosamine, chondroitin, and psyllium seed husk address real health concerns for Maine Coons, and green tea extract adds functional antioxidant value. Joint supplements are meaningful for Maine Coons, but they can't rescue the overall ingredient quality. The formula still leads with chicken by-product meal, doubles up on both corn and rice, and relies on wheat gluten and corn gluten meal for plant protein padding. If joint support is your priority, you could pair a higher-quality base food with a standalone glucosamine supplement and come out ahead on both nutrition and cost. Shop on Amazon →