ARE DOGS OMNIVORES?
It was long held that because dogs had been domesticated for thousands of years and survived off the (s)crap we humans fed them and that they scavenged; that dogs had evolved and become omnivores. Like the human genome project, there was a dog genome project done. It was discovered that dogs are 99.97% related to the grey wolf - direct descendents. In fact, evolution takes place over millions, not thousands of years. And as a result, dogs went from being classified as canis familiaris to canis lupus familiaris, (a variety of wolf), in 1993. They are part of the canidae family of the order carnivora.
Like most carnivores, dogs hold the classic features. Teeth used for holding, ripping, shredding, shearing and tearing - not molars to grind. (Bears, while in the same order are not true carnivores as they have nice flat molars to grind up plant matter.) Powerful jaw and neck muscles to pull down prey and assist in chewing bone, meat and hide. Their jaws are hinged to open wide and gulp down large chunks of bone and meat. Skulls are heavy and shaped to prevent lateral motion of lower jaw when captured prey struggles. (The mandibular fossa is deep and C-shaped permitting only an up and down crushing motion, whereas herbivores and omnivores have flatter mandibular fossa allowing for lateral motion for grinding plants.) Highly elastic stomachs to hold large quantities of bone, meat, organs and hide. Stomachs are simple with an undeveloped caecum. A short foregut and short, smooth unsacculated colon, to process food quickly - not the long gut necessary to process plant food. They lack the salivatory enzyme amylase, which is needed to break down complex carbohydrates. You will find that fruits and veggies fed to your dog, pretty well come out the same way they went in!
Since most Veterinarians have minimal teaching about nutrition, and most of that comes from the dog food manufacturers, it is a common misconception that dogs are omnivores. It is a cheap filler for the dog food manufacturers to include grains and veggies to your dogs diet. Also, it appeals to us as humans to see a package covered in, what we consider to be, healthy food. But that is healthy food for US not DOGS!
I'm going to use several quotes from the book of L. David Mech, chair of the World Conservation Union's IUCN Wolf Specialist Group, who leads the global scientific community in wolf research. He is an adjunct professor at the University of Minnesota and senior research scientist with the U.S. Geological Survey. "Those who insist dogs did not descend from wolves must disprove the litany of scientific evidence that concludes wolves are the ancestors of dogs." And, as we have already established, the wolf is a carnivore. Since a dog's internal physiology does not differ from a wolf, dogs have the same physiological and nutritional needs as those carnivorous predators, which, remember, "need to ingest all the major parts of their herbivorous prey, except the plants in the digestive system" to "grow and maintain their own bodies" Wolves: Behaviour, Ecology and Conservation
Many times, people will advise that dogs are not true carnivores like cats are - known as obligate carnivores. But, dogs and wolves have the ability in times of lack of food, to change the protein requirements for their bodies. Cats do not have this ability and cannot survive on low protein. "Dogs, ... possess the ability to alter their enzyme systems to adapt to a diet low in protein and its constituent amino acids. (Meyer and Stadtfeld 1980)." "These enzyme adaptations occur on a scale of hours to days. Thus the animal conserves nitrogen from protein and survives in spite of a low protein intake. Of course, if a wolf has inadequate protein, it is probably starving, while a domestic dog might simply be responding to low protein in a diet that is energy-rich from carbohydrate additives. Nevertheless, dogs and wolves, can adjust their enzyme systems, in ways that cats cannot, as cat liver enzymes are permanently set for a medium to high protein diet." This has probably contributed to the idea that dogs are omnivores, when in fact, it is merely a mechanism used to save them from starving - hopefully a short term problem. Because dogs are being fed a totally improper diet, we are seeing the result in an increase in disease; auto-immune disorders and shortened life spans.
Pancreatitis is becoming a common and serious problem in dogs. Pancreatitis occurs when the pancreas is forced to help the liver detoxify the body. It's job is to produce enzymes, (like insulin), and help the liver for short periods of time, when the liver is overtaxed. A dog with pancreatitis is showing signs of liver damage - generally from the pesticides and poor food we are overwhelming it with. Many Vets will tell you that a dog with pancreatitis should not get high protein foods. Wrong! It is not the high proteins that cause the problems, but rather, the type of proteins. Proteins that have been overcooked - like in processed, manufactured foods; as well as foods high in fat are major contributors to the disease. Dogs do produce amylase in the pancreas - it is known as an induction process, whereby the pancreas is stimulated to produce amylase due to there being carbs in the diet, and in order to try and digest them. This constant strain causes pancreatitis and diabetes. It can also exhaust the pancreas causing an insufficiency. It is also estimated that many dogs suffer from low grade chronic pancreatitis.
It may also be suggested by people, that when wolves eat a kill, they eat the stomach contents of the herbivore first. Again, a misconception. Wolves try to get the main internal organs, (heart, liver, kidneys, etc.), via the soft, easy to tear abdomen rather than the difficult rib cage. As well, while they do eat the stomach, they shake out the contents first. "Wolves usually tear into the body cavity of large prey and pull out and consume the larger internal organs, such as, lungs, heart and liver. The large rumens, (weighing about 60 kg or 132 lbs. for a moose), is usually punctured during removal and its contents spilled. The vegetation in the intestinal tract is of no interest to wolves, but the stomach lining and intestinal wall are consumed, and their contents further strewn about the kill site. Smaller internal organs, such as kidneys and spleen, are then exposed and eaten immediately. Sometimes the rumen contents, with or without the surrounding rumen, freeze and become one of the few signs left of a kill in winter." "Wolves are not fed by meat alone; in fact they require the less palatable or less accessible portions of their prey in order to maintain a balanced intake of nutrients. In order to grow and maintain their own bodies, wolves need to ingest all the major parts of their herbivorous prey, except the plants in the digestive system." He goes on to say, "Bones from prey are required by wolves as the major source of calcium and phosphorus for the maintenance of their own skeletons. Bones, in fact, are a surprisingly well-balanced food for canids."
I think it's pretty clear that dogs are carnivores!