Royal Canin vs Science Diet Dog Food – Which Is Better And What’s the difference?

royal canin vs science diet

Check out my detailed comparison about Royal Canin vs Science Diet if you want to know which is better in 2021. 

Fortunately, more and more dog owners know that proper nutrition is a prerequisite for a healthy, long, and happy life. 

Many dog food manufacturers have also realized this fact. Examples include Royal Canin and Science Diet

In my current article, I have compared these two deservedly popular brands based on several aspects. 

I have found that the Science Diet contains better quality protein sources and is more affordable, but Royal Canin has a wider selection, and its recipes contain more omega-3 fatty acids. 

My goal is to help you decide which is the better choice for you and your dog.

Let’s start!

Why you should trust me

Whether you’re experienced in dog and other pet topics or not, I’m sure you’re in the right place. I do my best to provide the best and most reliable information possible to my readers.

My name is Peter Laskay, and I have been a pet lover since I was a child. One of the most important places in my life is to gain as much knowledge as possible about pet care. And I want to pass this knowledge on to my blog visitors.

Should you have any questions at any time, feel free to contact me using the contact information on the website.

History of the two brands

Before analyzing the two dog food brands in more detail, I would like to examine their history. As you will see, both companies have a huge reputation and are highly recognized in the pet food industry.

Royal Canin History

Royal Canin was founded in 1968 by Jean Cathary. Cathary was a French veterinarian who noticed that many dogs have skin and coat problems. That’s why he developed his own cereal-based recipe. 

The recipe successfully alleviated pet complaints, so he registered it under the name Royal Canin. The company’s reputation continued to spread, and it soon became the most recognized pet food manufacturer in France. 

From the 1970s, the brand began to spread throughout Europe. Cathary sold the company to the Guyomarc’h Group in 1972, which was a much larger animal feed company. 

In the following years, the group established subsidiaries in several European countries. Their goal was expansion. 

In 1980, the brand introduced the recipe for large breed puppies. This has also served as an example to other manufacturers in developing a diet to suit individual needs. 

Since 1985, exports to the United States have steadily increased. In 1990, the Guyomarc’h Group was acquired by Paribas Bank, which further enhanced Royal Canin’s reputation in later years. 

Finally, the brand fell into the hands of Mars Inc. in 2001. Royal Canin is rightly one of the most popular foods for dogs and cats in the world today.

Hill’s Science history

The history of Hill’s Science began in 1939. A blind man named Morris Frank asked his veterinarian to help his guide dog with kidney failure. 

The veterinarian, whose name was Dr. Mark Morris, concluded that Mr. Frank’s dog’s problem was malnutrition. That’s why he started working on a formula that could contain the right nutrients to treat the disease. 

The dog food worked. Many dog owners have bought it, as a proper diet has proven to be a good solution to many health problems. 

Nine years later, the demand for dog food grew so much that Dr. Morris began working with the Hill packaging company. Together, they created the Hill’s Science Diet, which continues to enjoy unbroken popularity today. 

The Colgate-Palmolive group currently owns the company. Many dogs and cat foods are sold in 86 countries around the world. Hill’s name today is synonymous with quality, and plenty of veterinarians give these formulas to their own pets.

Royal Canin Product lines

Royal Canin dog food products can be divided into three ranges. Size based and Breed-specific diets are commercially available. Also, there is the Veterinary diet range, which includes prescription products.

Royal Canin Size nutrition 

In this product line, wet and dry foods are available for giant, large, medium, small, and toy breeds. 

In addition to the dogs’ size, we can also choose a recipe based on different health considerations. Examples are digestive health, coat and skin health, or joint support. 

These products are available in two flavors: chicken and pork.

Royal Canin Breed nutrition

Royal Canin is a brand that also has a breed-specific line. The nutritional needs of different breeds, common health problems, and other important aspects have been considered in producing these products. Wet and dry food can also be found in this line.

Royal Canin Veterinary Diet

There are diets in this line that veterinarians usually recommend. There are plenty of recipes for chronic diseases here. It is important to know that all of these diets are prescription. For this reason, be sure to talk to your vet before ordering from this line.

Hill’s Science diet products

The Science Diet is one of Hill’s product lines. Wet and dry foods, as well as treats, can also be found here. 

Although these products are not prescription, they are often recommended by veterinarians. The manufacturer’s goal with these recipes is to ensure that pets live the longest and healthiest life possible through proper nutrition. 

Whether you are looking for a special diet (e.g., grain-free) or want a solution to a health problem (skin and coat health, joint problems, etc.), Hill’s Science products are sure to find the right one for your dog. 

Not to mention that foods of all sizes and ages are available in this line.

Royal Canin vs Science Diet: Nutritional Value Comparison

The quality of dog food fundamentally determines how it will affect your dog’s health. This is because a specific diet can cause or even eliminate allergic or sensitivity complaints. 

If you are aware of your dog’s individual nutritional needs, you may want to choose a product accordingly. Different diets can mean other ingredients and nutrients. 

Below, I will contrast some products of the two brands. To make the comparison balanced, I will choose dog foods for similar purposes. 

Since Hill’s Science doesn’t offer formulas for specific breeds, I don’t choose them from Royal Canin’s offerings either. 

So I chose a large breed, a medium breed, and a small breed formula from both brands. You can see these below with the key features. I will analyze them in detail later.

Each product’s packaging contains the guaranteed analysis, which shows the recipes’ protein, fat, and fiber content. All products comply with the AAFCO Nutrition Guidelines for Dogs.

Large breed formulas:

Royal Canin Large Digestive Care Dry Food

Key features:

  • Great for dogs with sensitive stomachs
  • Contains probiotics and dietary fibers
  • Great nutrition for large breeds
  • Promotes healthy gut flora

Hill’s Science Diet Adult Sensitive Stomach & Skin

Key features:

  • Contains prebiotic fibers
  • Supports the digestive system
  • Contains vitamins, and minerals
  • Recommended by veterinarians

Medium breed formulas:

Royal Canin Medium Digestive Care Dry Food

Key features:

  • Formulated for medium-sized dogs
  • Contains prebiotics, dietary fibers, and easily digestible proteins
  • Designed to promote healthy gut flora
  • Delivers targeted nutrition

Hill’s Science Diet Adult Chicken & Barley

Key features:

  • Contains omega-6 fatty acids, vitamin E, and other useful nutrients
  • Supports a healthy immune system
  • Free of artificial ingredients
  • Helps maintain strong, lean muscles

Small breed formulas:

Royal Canin Small Digestive Care Dry Food

Key features:

  • Formulated for little dogs with sensitive bellies
  • Contains prebiotics, dietary fibers, and easily digestible proteins
  • Delivers targeted nutrition
  • Promotes healthy gut flora

Hill’s Science Diet Adult Sensitive Stomach & Skin

Key features:

  • Contains prebiotic fibers
  • Contains Omega-6 fatty acids, vitamin E, and other useful nutrients
  • Optimal balance of nutrients
  • Contains added vitamins, and minerals

Large breed formulas comparison table:

Brand:Royal CaninHill’s Science
First 5 ingredients:Chicken By-Product Meal, Brewers Rice, Brown Rice, Corn Gluten Meal, Chicken FatChicken, Brewers Rice, Chicken Meal, Yellow Peas, Cracked Pearled Barley
Main Protein SourcesChicken By-Product MealChicken, Chicken Meal, Egg Product
Main Carb sources:Brewers Rice, Brown RiceBrewers Rice, Yellow Peas, Cracked Pearled Barley, Whole Grain Sorghum
Other ingredients:Dried Plain Beet Pulp, Fish Oil, Wheat Gluten, Pea Fiber, Sodium Silico Aluminate, Vegetable Oil, Added vitamins, and mineralsChicken Fat, Soybean Oil, Dried Beet Pulp, added, vitamins, and minerals
Protein content26%21%
Fat Content:16%12%
Fiber Content:3.8%4%
Kcal:343 kcal/cup382 kcal/cup
Price rating:4.34.6

Medium breed formulas comparison table:

Brand:Royal CaninHill’s Science
First 5 ingredients:Chicken By-Product Meal, Corn, Brewers Rice, Chicken Fat, Brown RiceChicken, Cracked Pearled Barley, Whole Grain Wheat, Whole Grain Corn, Whole Grain Sorghum
Main Protein SourcesChicken By-Product MealChicken
Main Carb sources:Corn, Brewers Rice, Brown RiceCracked Pearled Barley, Whole Grain Wheat, Whole Grain Corn, Whole Grain Sorghum
Other ingredients:Beet Pulp, Fish Oil, Vegetable Oil, Pea Fiber, Added vitamins, Probiotics, and mineralsCorn Gluten Meal, Soybean Meal, Chicken Fat, Dried Beet Pulp, Soybean Oil, Pork Flavor, vitamins, and minerals
Protein content23%20%
Fat Content:16%11.5%
Fiber Content:3.7%4%
Kcal:321 kcal/cup363 kcal/cup
Price rating:4.34.6

Small breed formulas comparison table:

Brand:Royal CaninHill’s Science
First 5 ingredients:Chicken By-Product Meal, Corn, Chicken Fat, Brewers Rice, Corn Gluten MealChicken, Brewers Rice, Chicken Meal, Yellow Peas, Cracked Pearled Barley
Main Protein SourcesChicken By-Product MealChicken, Chicken Meal
Main Carb sources:Corn, Brewers RiceBrewers Rice, Yellow Peas, Cracked Pearled Barley, Whole Grain Sorghum
Other ingredients:Natural Flavors, Wheat Gluten, Dried Plain Beet Pulp, Fish Oil, Vegetable Oil, Pea Fiber, Added vitamins, Probiotics, and mineralsEgg Product, Chicken Fat, Soybean Oil, Brown Rice, Dried Beet Pulp, Chicken Liver Flavor, vitamins, and minerals
Protein content28%21%
Fat Content:20%12%
Fiber Content:3.6%4%
Kcal:485 kcal/cup392 kcal/cup
Price rating:4.54.7

Meat and protein content

royal canin vs science diet

Protein is the most important part of a dog’s diet. This is because protein provides the amino acids that play a key role in many bodily processes. 

Amino acids build muscle mass and are responsible for cell regeneration. For this reason, it is no coincidence that I usually check the protein content of dog food first. 

It is clear from the tables that Royal Canin products have more protein content. Of course, the 20-21% offered by the Science Diet is enough for the average dog

What is more important than quantity is quality. The first ingredient and the primary protein source in Royal Canin recipes is the chicken by-product meal. 

It is not considered a high-quality protein source, although it contains a lot of glucosamine and chondroitin. These two minerals have an excellent effect on joint health

On the other hand, science diet products include real meat, which is considered better in all respects than a by-product. 

In short, although Royal Canin contains more protein on average, the quality of protein sources is better in Science Diet.

Fat content

royal canin vs science diet

Fat is a beneficial source of energy. Besides, this nutrient is involved in many processes and helps utilize fat-soluble vitamins. 

Royal Canin products generally have more fat. However, this is not necessarily a problem. It is worth noting that excessive fat intake increases the risk of obesity for older or less active dogs, which carries additional health risks. 

It is also worth mentioning fatty acids concerning fats. Omega-3 and omega-6 fatty acids have anti-inflammatory effects and promote brain, immune system, skin, and coat health. 

Royal Canin products usually contain fish oil, which is an excellent source of omega-3s. Science Diet products have fewer of these ingredients. 

Therefore, in terms of fats, Royal Canin wins, but pay attention to your dog’s calorie intake.

Fiber Content

royal canin vs science diet

Although fiber is not an essential and digestible nutrient, it is important in several ways. On the one hand, it has a good effect on the intestinal flora as it serves as a nutrient for beneficial bacteria in the intestines. This will make the digestion of the dogs much healthier. 

On the other hand, the fiber content of nutrients slows absorption, keeps blood sugar levels even, and helps with weight management due to fullness. 

There are not many differences between the two brands in terms of fiber. Science Diet products contain a little more fiber on average.

Other ingredients

Both brand’s products contain controversial or questionable ingredients. Inexpensive fillers such as corn, wheat, or soy are not considered nutritious carbohydrate sources. Also, they can cause sensitization or allergies in many dogs. It is important to be aware of whether your dog can eat these ingredients.

Flavors and options

Like humans, dogs sometimes get tired of tastes. Some dogs like chicken or other poultry, while others prefer red meat. Fish is also a pretty good option. For this reason, it doesn’t hurt to have a brand with a wide selection in terms of flavors as well. 

Both brands offer a variety of flavors, and food forms are similar for both. 

It’s important to note that if, for some reason, you need to switch between flavors, do it gradually. A rapid change can cause digestive problems in dogs.


royal canin vs science diet

I always say you shouldn’t buy the cheapest dog food. Because you get what you pay for. However, there is no problem if you buy the more affordable of the two right quality products. Science Diet formulas are always available at a better price, so this brand wins this round.

Recall history

Safety is an important consideration when choosing the right dog food. If a brand receives many complaints and there is a health risk or other problem, the FDA may request a recall. For this reason, in a review, I always look at ongoing and past recalls. 

You can find a list of current recalls here.

Both brands have received some recalls in recent years. You can find these below, along with the reasons.

Royal Canin Recalls

  • February 2006 – Too much Vitamin D3
  • April 2007 – Melamine
  • May 2007 – Melamine

Science Diet Recalls

  • March 2007 – Melamine
  • June 2014 – Potential for salmonella
  • November 2015 – Labeling issues
  • January 2019 – High levels of Vitamin D

As you can see, Royal Canin had fewer recalls, so in this respect, it is the winner

Real Customer Reviews

Examining customer reviews allows us to get a complete picture of a given product. This will show you the pros and cons of a product and how many 5-star and other ratings it has. 

Below, I have collected positive and negative reviews of popular products from the two brands. Each is from Chewy’s website.

Royal Canin Large Digestive Care

This recipe was developed to treat digestive problems. And customers are usually delighted with that. The product has been shown to prevent and treat diarrhea, loose stools, bloating effectively, and other problems. Plus, even the pickiest dogs like the taste of it. 

Overall, there are few complaints about the product, and it is usually related to packaging, price, or shipping issues.


Instantly fixed everything.

  • This food instantly fixed my 16-month-old Dutchie/GSD mix’s chronic soft stool and frequently poor quality bowel movements. He was on Royal Canin adult food, having had no issues with Royal Canin large breed puppy food. Since his stomach was already upset when the new food got here I didn’t bother switching him to the sensitive stomach food slowly but opted to change to the new food all at once and late the next day all of his issues were gone.

Wow! What A Difference!

  • I bought this for my young male Doberman who has some stomach issues. He loves the kibbles as well as the corresponding canned food, and his diarrhea has completely disappeared. However…… older female, pickiest eater in the world, LOVES this stuff! More importantly, we are seeing a huge difference in her playfulness, energy, and attitude. We are on our second bag, and while I would rather fix my dogs homemade chicken, turkey, and such, they PREFER the Royal Canin kibbles and canned. Crazy, but true.


Trusted food that agrees with her stomach

  • Our vet highly recommended Royal Canin so we chose this food for our 60 pounds 2.5-year-old mixed breed dog. She gobbles it up (though she’s not a picky eater). This has greatly improved digestion for her. There are two things I don’t like – 1. I wish the resealable bag actually worked (the seal always breaks in the first week of opening) and 2. The kibble doesn’t fit in any of our feeder toys because it’s so big. I know RC does a lot of research and the size is specifically made for the size of the dog… but we miss being able to use her toys!

Great Quality Food

  • The only reason I didn’t give it a 5 is that it’s expensive.

Hill’s Science Diet Adult Sensitive Stomach & Skin

Many customers report that this formula helps dogs with digestive and skin problems. In terms of taste, the situation is different. Most dogs love this Hill’s product very much, but there are reviews that picky dogs don’t like it.


Picky eater and sensitive skin

  • OMG! I can’t say enough great things about this food! My fur baby(Killian) would go 2-3 days not eating! I’ve had her into the vet and they had no idea why she wasn’t eating! I tried all kinds of foods and nothing worked until we tried Hills Science Diet! She acts like a puppy again, she’s 6 now.

Finally! Our Weimaraner is eating!

  • We have a Weimaraner who has a very sensitive stomach. He will refuse to eat if the food doesn’t settle right with him. We tried every sensitive stomach food/ not cheap ones/ that we could find. He might eat grudgingly for a while and then refuse. He is once again happy at mealtime with Hills Sensitive Stomach & Skin Chicken! There is even a bounce in his 11-year-old step again! Yah Emory!


Good food, but why the change in kibble size?

  • We’ve been using this food for our two Great Danes for about six months now, and it agrees with both of them (miracle of miracles). The overall quality of the brand is excellent; however, we noticed that the kibble is much smaller in the last bag we received. One of our dogs is now eating it too quickly and vomiting before it’s fully digested. The overall formula seems to be the same – I’m wondering why there was a need to change the kibble size? Unfortunately, we may have to switch foods because of this change.

Okay for his digestive issues… but dog really doesn’t want to eat it

  • I’ve never had a problem with my dog not liking food… but he really doesn’t like this one. I’ve had to crumble cheese on top of his food for the last month to get him through the bag. What’s strange is that last week I picked up the large breed one (hound on the front) not realizing there was a difference and he gobbled that up as soon as it hit the bowl. Other than the kibble size, idk what’s different between the two- but if your dog is like mine and turns his nose up this one, try the large breed version (if your dog can handle the bigger kibble size).

My final verdict about Royal Canin vs Science Diet

I went through several aspects of my article to find out which is the better brand. Both have a solid history, which is why we know that the two manufacturers are very keen to produce quality dog food. 

And what is the answer to the question of which is better? 

Science Hill uses significantly better protein sources, but Royal Canin is more beneficial for fats. 

Science Diet products have lower prices, while Royal Canin offers diets for specific breeds. 

I can’t announce an absolute winner in this article. Considering the above, choose the brand that best suits your and your dog’s needs.

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Peter Laskay

Peter Laskay

Hi there, my name is Peter Laskay and I am the person behind this site. I’ve been a fan of pets since I was a little kid and want to help people with similar interests. I want everyone to be able to provide the most appropriate care for pets.