Somehow the notion that dogs are pure carnivores has permeated through internet chat forums, among some non-medically trained people working in the pet industry (groomers, trainers, etc.), and those that take their information seriously. This notion is based by in large on the multiply erroneous notion that dogs are essentially wolves, and since wolves are pure carnivores, then dogs necessarily should be fed as wolves would eat.
I stated multiply erroneous notion because the true fact is that EVEN WOLVES ARE NOT PURE CARNIVORES! While it is true that wolves generally require and eat a high level of protein in comparison to dogs, they also consume a significant amount of vegetable matters instinctively, as doing so is necessary for optimal physiological balance and gastrointestinal health in the species. Wolves consume vegetation from routine grazing on grasses and by tearing open the stomachs of their herbivorous prey and eating the contents.
The other true fact is that dogs are not wolves, but differ from the wolf in DNA structure by about 0.8 %. That may not seem like much, but only a 1.2% difference in DNA separates us from the chimpanzee. Few would suggest that we should model our diet around that of a chimpanzee.
Thousands of generations and selective breeding that made domestic dogs more adaptable to life with humans was responsible for the evolution that today differentiates dogs from their ancient ancestor. Among the most prevalent difference between dogs and wolves that resulted is gastrointestinal physiology and how it impacts overall gastrointestinal and other organ health. In the process of canine domestication, humans essentially their early more wolf-like canine companions what they ate, and over successive generations, the species adapted to a more omnivorous diet.
Dog owners jumping on board with feeding their dogs nothing but meat, essentially a pure protein diet, is fraught with potentially serious health consequences. All one has to do is understand protein metabolism to see the problem.
Before protein can be absorbed into body’s cells and tissues for metabolic and physiological purposes, it must first be broken down into small chains of proteins called peptides, and in some cases broken down to the individual molecular protein building blocks, amino acids. Once absorbed by the gut, amino acids and peptides are then repackaged and utilized by the body.
It all sounds lovely, but protein metabolism does not come without a price, as it generates a toxic waste product called ammonia. In fact, many common meat protein sources are as low as 78% utilized by the body with the rest represented as waste. Luckily, like us, canines have a liver that converts ammonia into a less harmful molecule called urea, which is then excreted by the kidneys in urine.
However, the liver and kidneys over time become overwhelmed with a diet heavily laden with protein, because these organs are constantly burdened with detoxification. Over time, if excessively taxed in this manner through diet, these organs become compromised, leading to degenerative disease, chronic renal failure in the case of the kidneys, and cirrhosis in the case of the liver.
Physiologically, dietary protein for the average adult canine should not exceed 25% of the total daily nutrient intake. In high performance dogs, such as those that participate in in field or agility competition, that requirement may be increased to 27%. Beyond this level of protein the dog suffers deficiencies in other key nutrients, such as soluble and insoluble fiber and anti-oxidants to name a few, while unnecessarily taxing his liver and kidneys with excessive protein metabolic waste.
Canine owners that feed raw are the biggest offenders with regard to overloading their dogs with protein, many feeding nothing but a raw meat diet. For these pet owners that are committed to raw feeding, if they are feeding their dogs nothing but meat, I would urge them to integrate fresh or cooked vegetables to represent at least 50% of total dietary intake. Green beans, carrots, broccoli, celery, and spinach are all healthy vegetable sources for dogs. It is also a good idea to integrate complex carbohydrate sources, such as brown rice and sweet potato, as well as some canine safe fruits like cantaloupe, apples, and pears.
What is most troublesome to me is that some commercial pet food companies are taking advantage of the canine pure carnivore hype and creating diets that are heavily laden with protein, even going further to validate this false notion in their promotional tactics. I was actually inspired to write this post after having seen a TV commercial two nights ago from a large, well known pet food company touting its newest diet as having one of the highest protein percentages in the industry.
I caution all canine owners to not buy into the hype, not listen to non-medically trained people that recommend a dietary regimen without understanding that over time it does damage to the liver and kidneys while denying the canine other essential nutrients; and reject pet food companies touting false claims, who clearly value sales far more than the well-being of their canine consumers. If in doubt, talk to your veterinarian to help you sift through what is best to feed your dog.
Dr. Roger Welton is the President of Maybeck Animal Hospital and CEO/Chief Editor of the veterinary information and blog online community, Web-DVM.
