By Roxanne Stone MSc
With the advent of the industrial revolution and the rapid depletion of small family farms, our ancestral food chain has seen significant changes within the last 100 years, and not altogether for the better. The mass migration of people into cities and away from small villages and farms has influenced our food industry to move to overly cooked, heavily processed, low quality, convenience foods.
Unfortunately, these same foods have made their way into the bowls of our companion animals and they are experiencing many of the same human health repercussions as a result. Historically, cooked foods have never been a part of the canine and feline diet, rather they have subsisted and thrived off live prey, fermented carrion, and they foraged for any scraps they could obtain. They have only been introduced to cooked and processed foods within the last 80 years.
Looking back at the historical diets of dogs and their wolf ancestors, it is clearly evident that they are carnivores. Their teeth, gut and digestive physiology strongly support this. Dogs have hinged, powerful jaws along with canines and triangular shaped carnassial teeth for the ripping and tearing of flesh and crushing of bone. They do not have the typical molars for the grinding of plant material or a four chamber stomach for the slow digestion and fermentation of complex carbohydrates (starches from plants and grains). They have a large stomach, short digestive tract and very small cecum, indicative of consuming large amounts of high protein food in a short time period and for fast digestion and rapid absorption of nutrients. 1 In the wild, these canines could typically go many days between their meals.
Why are 90% of animal caretakers feeding their carnivore companions a dry kibble diet consisting of at least 60% carbohydrate, very little moisture and minimal, low quality protein? Much of the pro- tein in commercial kibble diets is also plant based. Expecting our pets to graze on this type of diet all day long, and be satisfied both physically and nutritionally, does not make sense. Without going into too much detail on the history of dry commercial kibble diets, the short end of the story is that it was introduced in response to the high cost of meat during the Great Depression and was heavily promoted at the end of WWII when it gained popularity for its convenience, ease of distribution and low cost.
If our pets have managed to survive off this cheap, convenient, low quality protein source for the last 80 some years, why should we be concerned about it? Even though our pets may be surviving off commercial kibble, can we really say that they are thriving on it? The answer is pretty clear. Chronic degenerative diseases, auto-immune diseases, allergies, kidney, pancreatic and liver disease are all rampant within our pet populations and cancer rates continue to rise. 2
A study conducted in Stockholm, Sweden by Dr. Kollath showed that young animals fed a cooked, processed diet initially appeared to be healthy, but once they reached maturity, they began to rapidly age and develop degenerative disease symptoms. The control group that was raised on a raw, uncooked diet did not age as fast and showed no degenerative disease symptoms but remained healthy. Another study out of Belgium, “Relation Between the Domestic Dogs’ Well Being and Life Expectancy, a statistical essay”, utilized data gathered from more than 500 domestic dogs over a consecutive five year time period (1998-2002). The authors, Lippert and Sapy, were able to statistically show that dogs fed a homemade diet, consisting of high quality foods used from their owners’ meals versus dogs fed an industrial, commercial pet food diet had a life expectancy of 32 months longer – that’s almost 3 years!
What many unsuspecting caretakers are unaware of, is that in addition to substandard ingredients, there are many forms of toxins introduced into our pets’ bodies through these highly processed, cooked, kibble diets. These toxins include: aflatoxins, heterocyclic amines, acrylamides, and most recently discovered in dry, cooked pet foods, PBDEs (polybrominated diphenyl ethers) a chemical used as a flame retardant. 3
Grains such as corn, wheat, and rice, as well as nuts and legumes, are often contaminated with molds, either pre or post harvest, as a result of poor growing conditions or substandard or extended storage. These molds can easily grow and produce a very potent carcinogen (aflatoxins). The aflatoxins are very stable and high temperature processing steps will not render them benign. Exposure to these toxins, even at low doses, can wreak havoc on your dog’s system, causing anemia, liver or kidney failure, cancer and premature death. 2 Even if your kibble is grain free, it still contains a high carbohydrate content, so there is the potential for mold spores to contaminate the kibble during storage, especially if it is exposed to a moist environment. This can also happen in your home if your kibble is stored in a moist basement or an open container.
Many scientific studies have established the presence of mutagenic, cancer causing substances such as heterocyclic amines as a result of cooking meat and fish, and have additionally demonstrated a relationship between dietary heterocyclic amines and cancer. 4, 5, 6, 7 A 2003 study that sampled 25 cooked, commercial, store bought pet foods showed that all but one tested positive in their mutagenic test, and a subset of 13 of these same samples were tested and confirmed the presence of heterocyclic amines. 4
Both the EPA (Environmental Protection Agency) and WHO (World Health Organization) have classified acrylamide as “a probable carcinogen”. Studies show that acrylamides are formed due to the high temperature heat applied to vegetable foods; more specifically a reaction between the amino acid asparagine and the simple sugars found in these foods. Whether that food is fried, baked, roasted or extruded, these substances have been measured at many levels, and in some studies, there are significantly high levels. Factors that contribute to acrylamide formation are the lack of remaining moisture in the product and the surface area. These two attributes are found in every type of kibble, which are all low in moisture.
PBDEs (polybrominated diphenyl ethers)
Although further studies are needed to determine if there is a direct toxicological effect from PBDEs, it is still alarming to learn of the presence of these chemicals, most commonly used as flame retardants in many household products, in our commercial pet foods. A recently published study in the Journal of Environmental Science and Technology revealed that the average blood concentration of these PBDEs was as much as ten times higher in tested dogs than in humans. The researchers also found the presence of PBDEs in dog food samples and at higher levels than in meats sold for human consumption. The authors suggest these PBDEs found in the dog food may be a result of processing rather than contributed by the food source itself. 3
Commercial kibbles not only harbor harmful toxins, they are also stripped of much of their nutrient value, becoming a “dead” food product. 2 Unfortunately, many well intentioned consumers who want to give their pet a high quality commercial diet choose to buy expensive, “grain free” kibbles, with claims of all natural – or even organic – ingredients, believing they are purchasing a more nutritious pet food. But the fact is, even if these kibbles contain high quality ingredients with no preservatives, fillers or additives, they are still going through a cooking process which ultimately nullifies much of the nutritional value these quality ingredients would have contributed. The kibble is left with proteins that have been denatured, enzymes that are rendered inactive, and any natural, beneficial microflora (good bacteria) are no longer viable. These components are all extremely important and provide a synergistic effect for the complete digestion, absorption and assimilation of nutrients from the food. Manufacturers try to add back some of the lost nutritional value with synthetic vitamins and minerals so their formulas comply with AAFCO standards and they can call their food “complete and balanced” on their label. However, studies show that these synthetic vitamins can actually cause more harm than good to our pets, because the body cannot completely utilize them and instead it will processes them as a foreign substance, causing more stress to the liver and kidneys. 2
Sadly, our environment is already saturated with many pollutants and toxins which we cannot avoid. Why not take control and avoid the ones we can, for both ourselves and our pets? In order to defend against these environmental pollutants, our pets’ bodies need a strong, well established, healthy immune system. The best way we can power our pets’ immune system is with whole, live, nutrient dense, raw foods. 2, 8
A raw, species appropriate diet is the best defense we can give our pets to thrive and maximize their opportunity for a long, healthy life. As caretakers of these amazing companion animals, who unconditionally enhance our lives, we feel that it is not only fair to provide this to them, but rather our responsibility.
- Mills, Milton R., MD. The Comparative Anatomy of Eating. Nov. 2009. http://www.vegsource.com/news/2009/11.
- Knueven, Doug, DVM, CVA, CAC. The Holistic Health Guide, Natural Care for the Whole Dog. (2008).
- Lippert, Gerard, DVM and Sapy, Bruno, DVM. Relation Be- tween the Domestic Dogs’ Well-Being and Life Expectancy. (2003).
- Venier, Marta and Hites, Ronald. Flame Retardants in the Serum of Pet Dogs and in Their Food. Environ. Sci. Technol. 2011, 45 (10):4602-4608.
- Pasternak, Henry, DVM, CVA. Healing Pets with Nature’s Miracle Cures. (2001): 13, 63-80.
- Felton, J.S., M. Jägerstad, M.G. Knize, K. Skog, K. Waka- bayashi, Contents in Foods, Beverages and Tobacco, in: M. Na- gao, T. Sugimura (Eds.), Food Borne Carcinogens: Heterocyclic Amines, Wiley, West Sussex, 2000, pp. 31–71.
- Knize, M.G, Salmon, C.P., Felton, J.S. Mutagenic Activity and Heterocyclic Amine Carcinogens in Commercial Pet Foods. Mutagenic Research/Genetic Toxicology and Environmental Mutagenesis. August 2003 539 (1-2): 195-201.6.
- Rohrmann, S., Hermann, S. and Linseisen, J. Heterocyclic Aro- matic Amine Intake Increases Colorectal Adenoma Risk. Am J Clin Nutr. May 2009 89 (5): 1418-24.