Common Myths and Misconceptions About Dog Food

alk down the aisle of your local pet supply store and you'll be inevitably confronted with an overwhelming and confusing display of dog food choices.

You can find brands for dogs of different sizes, ages, activity levels, lifestyles and even breeds. And within each of these categories, you must then further choose among food types (cooked, raw, dehydrated, freeze-dried, extruded, canned), preferred ingredients (grains or grain-free, chicken, beef, salmon or lamb, potato or tapioca), and the inclusion of added nutrients (omega-3 fatty acids, glucosamine, antioxidant vitamins).

To add to the problem, pet food labels are hard to decrypt and can be misleading. It's also hard to remain objective about what dog food to buy when we're constantly bombarded with the marketing hype and the dubious health claims that typify the pet food industry.

It's no wonder that many confused dog owners turn to their veterinarian, their dog trainer, their next door neighbor, or their favorite Facebook group for advice on what food to buy.  

In this article, we’re going to debunk some of the most common claims, beliefs and misconceptions about dog food. 

Are dogs carnivores?

This is a classic misconception. It originates from the confusion that arises from the dual use of the term “carnivore” that’s used both as a taxonomic classification, and as a description of a species’ feeding behavior and nutritional needs.

Both dogs and cats are classified within the taxonomic order of “Carnivora”, a group of mammals that includes over 280 different species. While many of the Carnivora species hunt and consume meat, not all are predatory or nutritionally carnivorous. The Giant Panda, for example, consumes mainly plant food, while the Grizzly Bear consumes both plant and animal food. 

Cats are “true carnivores”, which means that they’re incapable of surviving only on plant food, and must have some meat in their diet. In contrast, all of the canid species, including the domestic dog are omnivorous in their eating habits and their nutrient needs. In the wild, canids are opportunistic predators, hunting and eating whatever type of prey they can find. They also scavenge on plant foods and regularly consume fruits, berries, and mushrooms.

Anatomically, a dog's digestive system is consistent with that of other predatory omnivorous species. Dogs possess a stomach that can easily break down raw meat and bones, and a small intestine that is longer (relative to body size) than that of true carnivores, and shorter than that of herbivorous species. A dog’s complete digestion takes only 8 hours, one of the fastest in mammals (humans take 36 hrs to fully digest).

While classified as carnivores, dogs are, in practice, omnivorous, meaning they can use pretty much any food as fuel for energy. 

In short, the nutrient, metabolic and anatomical characteristics of dogs place them on the omnivorous side of the spectrum (like humans), within the wide range of species that hunt prey, scavenge and consume plant foods.

Nutrition Advice

An ideal balanced diet for a dog should be high in quality animal proteins and fats, complemented with low levels of digestible carbohydrates of various plant food origins.

A careful look at commercial dry food labels easily shows that these highly processed products do not fit the ideal dog food profile. Dry foods are typically high in carbohydrates (on average 70%), and low in protein (3-30% fresh, reduced to 10-12% once cooked).

How much should I feed my dog?

It’s estimated that over 50% of dogs in North America are overweight or obese. Obesity can shorten your dog’s life and lead to chronic diseases, such as diabetes, kidney disease, arthritis, liver failure, chronic gastrointestinal problems, low immunity, or even cancer.

A common misconception is to assume that the feeding directions written on food packaging are prescriptive. Feeding directions are recommendations, not rules. Overfeeding kibble is one of the main cause of dog obesity. Dry food is a highly concentrated source of calories that is high in refined carbohydrates (sugars).

I recently compared 12 different commercial dry foods sold as “adult dog maintenance”, and found huge differences in calorie counts varying between 280 and 540 (kcal/cup) within the same range of products. While these foods all claim to be "balanced", the wide variation of caloric values suggests otherwise.

You risk overfeeding a dog by following feeding recommendations on food labels without taking into account your dog's specific energy requirements and the proportion of nutrients needed. 

Nutrition Advice

Because a dog’s energy requirements always determines the quantities to feed, we should start by assessing our dog's daily caloric needs based on the amount of exercise he gets.  

As a general rule of thumb, a dry food that provides between 340 and 380 kcal/cup is suitable for a moderately active adult dog. If your dog is very active, a more energy-dense food, such as one that provides 400 to 480 kcals per cup may be more suitable.

You should measure food out in daily portions and weigh it with a food scale. This is especially important if you feed dry food because kibble density varies a great deal, so look at the values of calories per weight on the food label and not per cup. Remember to take into account in the daily calorie requirements what you anticipate to feed as treats .

A dog should be lean. If in doubt about how much to feed, look at the dog, not at the food.

Keep your dog lean and active - Dog Learner

Get an assessment of your dog’s daily requirements in calories from a vet or a nutritionist, based on your dog’s age, breed, activity levels, and general health. Then look at the calorie statement on the food label and adjust the quantity you serve accordingly.  

For more detailed advice on calories, read our article on how much to feed your dog.

Is home-prepared food cheaper?

The short answer is, it depends on the choices you make. 

If you feed your dog meat that's deemed fit for human consumption (which isn't the case of commercial pet food), you will probably end up spending more than on commercial products. You may have to shop around and buy frozen meat in bulk from discount stores.

If instead you feed dry food, look at the net quantity statement on food labels and do a cost-per-weight comparison between brands. Unfortunately, premium prices are not always a guarantee of quality. Mixing dry food and premium canned food will also raise the cost per weight significantly, and may end up costing more than home feeding.

Obviously, feeding home-prepared food to your dog involves more work than buying dry food. Researching balanced and nutritious recipes and buying fresh ingredients can be time-consuming. I guess that’s why kibble is so popular. Convenience and time saving comes at the cost of quality and nutritional benefits.

The food preparation itself doesn't have to be time-consuming. I recently met a breeder of police dogs who feeds a raw diet to 25 adolescent German Shepherds, and spends no more than 20 minutes daily preparing it. He's been doing this for years with amazing results.

Nutrition Advice

If you choose to prepare food yourself for your dog, you must follow nutritiously balanced recipes recommended by qualified animal nutritionists.

You should cook the grains, legumes and vegetables for better digestibility, and take safety precautions with handling and storing raw meat to prevent bacterial contamination.

Calorie estimation can be more difficult with home-prepared food, so monitoring your dog and weighing him regularly will help ensure that his weight stays constant and that you feed daily quantities that are adapted to his energy needs.

Is a raw food beneficial for dogs?

The question of the nutritional benefits of raw diets for dogs is a polemical subject. 

The fact is that to date, there are no data nor any published scientific studies that either support or refute any of the health claims that are declared for raw diets.

The reasons for the lack of research on the subject is easy to understand. Research studies are primarily funded by the pet food industry—hence a major conflict of interest. Understandably, many veterinarians, tend to err on the side of caution from a medical standpoint, and can also be conflicted by commercial interests (many sell pet food). 

The other problem is that the quality, nutritional balance and safety of home-prepared raw diets can vary greatly, making them almost impossible to evaluate reliably over time.

Critics of raw feeding focus on the potential for nutrient imbalances and purported increased health risks. The most frequently mentioned nutritional concerns are imbalances that occur when excess meat is fed along with insufficient amounts of other nutrients. The most prevalently cited health risks are the potential for bacterial contamination of raw meats and the risk of transmission to both pets and people. If bones are included, an increased risk of gut obstruction or perforation from bone fragments is also mentioned.

What to make of all that? 

While heat processing makes vegetables, fruits, and grains more digestible, it has the opposite effect on animal proteins. Heat processing also destroys essential nutrients.

Physiologically, dogs are equipped with a stomach that can break down raw meat and bones very efficiently thanks to high levels of acid and enzymes (100 times higher than humans), and protect from microbial infections. In the wild, canids can get sick, but the quality and safety of what they eat is greatly inferior to what can be prepared at home.

Nutrition Advice

As a nutritionist, I tend to favor a safely prepared raw meat diet, high in fresh quality proteins (salmon, chicken, lamb, eggs) and omega-3 fats (fish oils), complemented with cooked vegetables, grains and legumes. Commercial frozen raw foods are a good alternative to home-prepared diets, but are generally a more expensive option.

I personally trust and value the experience of many police dog breeders who have been feeding their dogs raw diets for more than 25 years with remarkable results. Working dogs have very high levels of energy requirements and can only thrive on quality diets. 

Is grain-free better for dogs?

Digestible carbohydrates, or starches, are found in legumes, cereals, and some vegetables, and provide the dog with a source of energy on the same level as proteins. 

Foods that are advertised as “grain-free” are those that exclude grain sources such as wheat, corn, rice, barley, and oats. In replacement, grain-free products include starches from other plant sources such as potato, peas, or tapioca. In general, grain-free foods tend to have a higher caloric density than grain-containing adult maintenance foods. Some grains contain gluten (cereals such as wheat, oats, and rye) while others don’t (corn and rice).

Two issues often come up when it comes to grains: digestibility and food intolerance.

Digestive sensitivity varies according to the size and breed of dogs, with significant anatomical differences. Large breeds have a much lower relative mass of gastrointestinal tract (2.8% of body weight) compared with that of small breeds (7%). Research studies have shown that digestibility is more critical in large breeds who better tolerate refined flours based on corn and rice, while small breeds are better fed on cereals, and need lower amounts of fiber in their diet.

Similar to the trend in human diets, interest in grain-free foods appears to have origins in increased recognition and diagnosis of gluten intolerance. For dogs, the grain-free issue isn't as medically relevant as for humans and serve mainly as a marketing tactic.

Despite current consumer biases toward gluten-free products, the fact is that current published studies of food allergy have shown that beef, dairy products, and soy are the most common causes of food allergy in dogs.

A very small number of dogs may develop a disorder called gluten-sensitive enteropathy (similar to Celiac disease in humans). However, this is a rare genetic disease that occurs primarily in Irish Setters, and is rarely diagnosed in other breeds.

Nutrition Advice

If you choose to buy commercial pet food, don’t believe the marketing hype and the so-called health claims about grain-free, and focus on the protein sources. Identify which protein sources are included (and in what proportions), and choose products that are high in protein and low in refined carbohydrates.

If you decide to prepare your dog's food yourself, get recipes and advice from a canine nutritionist to ensure the diet is nutritionally balanced and best adapted to your dog's life stage, activity levels and breed type. Mixing grain and non-grain starches is a good option, but you need to check that your dog can digest the food effectively. In doubt, ask your vet.


When it comes to dog food topics that are as sensitive and publicized as "natural" diets and grain-free, there is a typical case of confirmation bias at play on the part of customers. This is used by the pet food industry as a marketing ploy to sell products at a premium price by exploiting current belief and trends, with little scientific evidence backing it up.

Make the informed choice to learn to read the labels of commercial products to objectively determine what is more balanced and nutritious, or make the commitment to home feed your dog with quality fresh products and nutritious recipes.

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