Pet Food Myths

Although many of the resources consulted for this article are written by or endorsed by veterinarians, the information presented is not intended to replace veterinary care or advice.  Please do your research and consult a veterinarian you trust regarding your dog’s diet, health, and well-being, especially before making changes to the diet of pets that suffer from diabetes or other conditions.

When it comes to feeding our dogs, many of us have trouble separating fact from fable, and much of our confusion can be blamed on misleading advertising.  Pet food companies, in their efforts to push their products, have inundated us with exaggerations and marketing claims that many of us have accepted as fact, to the detriment of our pets. Many people recognize that advertising claims should be “taken with a grain of salt”, but what about so-called “experts” who have television shows or books?  Surely they would be resources for current, unbiased information. Or would they?

The information here is only a start; there is so much more to learn, and as with all subject areas and experts, there are conflicting opinions. I encourage people to do their own research from a variety of reputable, unbiased, well-supported resources.

Myth #1:  Dogs should never eat human food. 

The belief that human food is unhealthy for dogs, although widely held, is highly inaccurate.  As most of us are aware, there are some human foods that are harmful to dogs (i.e. chocolate, grapes, xylitol, onions, etc.) and there are some foods that are unhealthy to humans as well as dogs (processed food, junk food, candy, overly salty or fatty foods, etc.).  This is the main argument for the standard answer by the pet food industry when it recommends that people should not feed dogs table scraps. What isn’t said is that a lot of healthy human food is also healthy for dogs.  In fact, dog-safe human food is better for dogs than most dog food because of the low standards in the pet food industry.  Human grade meats, especially organic, non-medicated, free-range and grass-fed, are far superior to the questionable sources of protein in most commercial dog food.  This was aptly illustrated in the CBC documentary Pet Food: A Dog’s Breakfast  wherein an old pair of boots, in theory, could meet the minimum standards for protein in pet food.

The book Not Fit for a Dog! : the truth about manufactured dog and cat food (2009) also exposes the poor quality ingredients in manufactured pet food and suggests a strong association with it and many common health and behavioural problems in dogs and cats.  In the section entitled “Better Nutrition, Fewer Health and Behaviour Problems” the authors state that they know this is true because these problems “are ameliorated and often eliminated after the afflicted animals are fed … organically certified, biologically appropriate … whole food diets … that are neither highly processed nor full of synthetic additives/supplements” (p.144).  In other words, the problems lessen or go away when the pets are fed better food.  The authors, all veterinarians, are so certain of this they’ve included some recipes for homemade dog and cat food.

Compounding the problem of poor quality ingredients are the processing methods of most commercial dog foods, especially extruded kibble.  During processing, the ingredients are subjected to high temperatures that degrade most of the original nutrients.  There is also evidence that the high temperatures can create dangerous cancer-causing compounds, and tests have shown that most dry dog foods contain these (See Spot Live Longer, p.92).

The quality of the ingredients and the processing methods are not the only problems with most manufactured pet food.  Another problem is the high starch content, especially in lower-priced pet foods.  Grains and other starches can be cheap sources of protein and are necessary in the production of kibble, which requires a lot of starch. While it seems that dogs can digest some grains, cats have no known need for carbohydrates and they don’t digest them well.  This is one reason why many sources recommended that cats be fed canned food rather than kibble; the canned food tends to have more protein, less-grain based protein, and more moisture. Some veterinarians believe that the high amounts of grain in pet foods lead to obesity, diabetes, arthritis and food allergies.

In their book See Spot Live Longer: How to help your dog live a longer and healthier life! (2005) authors Steve Brown and Beth Taylor detail how grains might be the worst offender when it comes to the major ingredients in manufactured dry dog foods.  The low-quality grains used are often infested with storage mites and dangerous molds, and how we store the dry food in our homes often encourages the growth of the mites and molds. Storage mites are being linked to skin allergies in dogs, and molds produce mycotoxins that can affect the immune system resulting in long-term health problems or in extreme cases, immediate death.  Brown and Taylor caution pet owners who purchase kibble to upgrade to the best quality they can find and afford, purchase only enough that can be used in a week, keep it in its original package, put the bag in an airtight container (if the bag isn’t sealable), and store it in the freezer, if possible.  More information on the problems with storage mites and molds and how to store and handle kibble to help reduce these problems can be found in their book.

Myth #2: Feeding a dog human food encourages unwanted behaviours.

Dogs are opportunists.  Counter-surfing, garbage diving, begging, stealing from plates, food guarding, nipping: these are all behaviours that will continue if allowed.  It’s not a matter of human food; it’s a matter of training.  If you don’t want your dog begging at the table, don’t feed him at the table; put the table scraps in his bowl.  And since most dogs find human food far superior to their regular dog food or dog treats, you can use human food to train desirable behaviours to counteract undesirable ones.

Contrary to this myth, it can be argued that the feeding of commercial dog food encourages unwanted behaviours.  A dog that is voracious will have little self-control around food, and a lot of manufactured dog food lacks the nutrients and/or quality protein to keep a dog sated.  The authors of Not Fit For a Dog! believe feeding manufactured pet food can lead to a variety of unwanted behaviours such as  “constant food soliciting/hunger; increased aggression/irritability/hyperactivity” (p.145). As well, there is strong evidence that commercial dog foods are largely responsible for many of the medical conditions that can require dogs to be put on medications that cause an increase in appetite (i.e. Prednisone).

Myth #3: Dry food helps keep a dog’s teeth clean.

This is based on the idea that hard, dry kibble will help scrape the teeth clean.  This sounds logical, but it turns out to be lacking in evidence. Some debunk this myth by referring to the impossibility of a pet’s pointed teeth crunching the kibble enough for the scraping action to have any effect beyond the tips of the teeth. This is supported by the observation that when pets regurgitate their kibble, many of the pieces are still whole, having made it into the stomach without being crunched up.  Crunching kibble and dog biscuits does not dislodge plaque from dogs’ teeth and small bits of food can remain stuck to the teeth and contribute to plaque buildup.

There are certainly other pet food myths circulating, but these are three of the most common ones.  How do these ideas become so widely believed, especially since there doesn’t seem to be any evidence to back them up?  It looks like these myths were born largely because of the efforts of pet food companies to increase their profits.

One of the “problems” the pet food industry faced was people supplementing their pets’ food with table scraps.  Back in 1964, dog food companies began issuing press releases about dog care that promoted feeding dogs only commercial dog food and warned about the dangers of feeding table scraps.  This information appeared in newspapers and magazines and on radio stations.  Years later, dog food companies stressed the “science” of canine nutrition which was too complicated for the average person in the kitchen. These marketing strategies worked and the mantra “never feed your dog human food” was widely embraced. The pet food companies also wanted to increase kibble sales since it is cheaper to manufacture kibble than canned food. Hence the claim kibble “helps” keep a dog’s teeth clean was born, despite a lack of data to back it up.  Vague words are popular tools in advertising. (For more information about the history of pet food marketing, visit read the article “Pet Nutrition History”; it contains excerpts from The Long History of the Canine Race by Mary Elizabeth Thurston, 1996.  As well, read the first chapter in Raw & Natural Nutrition for Dogs: the definitive guide to homemade meals by Lew Olson, 2010.)

One doesn’t need a white lab coat and a science degree to feed a dog a well-balanced, species-appropriate diet, but it isn’t as simplistic as cooking them some hamburger and steaming some veggies.  There is a lot to learn, and despite the “bad apples”, there are pet food companies that do provide quality products. Educate yourself about pet nutrition and learn how to read pet food labels. Try starting with small changes and see the results.  Find an option that works for you and your pet.

Recommendations for small changes:

  • Try feeding some homemade “complete and balanced” dog food recipes
  • Change from kibble to canned, especially for cats.
  • Supplement kibble with some fresh, human-grade meats and steamed or finely chopped raw vegetables (focusing on leafy greens) (NOTE: always cook squash/pumpkin).
  • Upgrade your kibble. Look for brands with single source meats and fats, whole grains, and less toxic preservatives. The better brands are made from human-grade ingredients with little to no grains or any starches, and they often have packaging that will keep out moisture and air.
  • Feed a variety of foods from different animal proteins and rotate them on a daily basis.  Don’t mix them together; rotate them.
  • Avoid senior, “lite”, and diet pet foods because these are higher in carbohydrates and fibre and have reduced protein and fat; according to several resources, older and overweight dogs need fewer carbohydrates and better quality fats and proteins. NOTE: Senior dogs with kidney problems are often put on reduced protein diets. The authors of See Spot Live Longer claim that certain studies about aging dogs and protein consumption were misinterpreted which led to the belief that decreasing a dog’s consumption of protein could prevent further kidney damage.  The authors claim that these studies suggested that dogs with kidney damage should be fed better quality protein, not less protein (p. 159).



Dr. Becker’s Real Food for Healthy Dogs and Cats (2013) by Beth Taylor and Karen Shaw Becker DVM

Not Fit for a Dog! : the truth about manufactured dog and cat food by  Michael W. Fox, Elizabeth Hodgkins, and Marion E. Smart (2009)

Raw & Natural Nutrition for Dogs: the definitive guide to homemade meals by Lew Olson (2010)

See Spot Live Longer: how to help your dog live a longer and healthier life! by Steve Brown and Beth Taylor (2005)

Web resources: