One of the hot topics for argument about our pet food, is the one regarding whether dogs are either carnivores or omnivores. Until just a few short years ago there was little to no hard scientific evidence regarding the theory that our dogs are strict carnivores, similar to cats. As many will attest, plenty of dogs eat vegetable material. Some, like mine will drool lakes while watching veggies being cut for dinner, in anticipation of getting a few morsels tossed their way. The argument, however is whether they garner nutrition from these veggies or starches.
So what new evidence purported by the food industry proves that our dogs can do well on non-meat based diets? Actually there are none. Two unrelated studies published in two separate science journals, one in 2011 and the other in 2013, however, do provide evidence that there is more to the natural canine diet than just meat and bones. We are not promoting grain-based diets. We are supplying new scientific evidence, for you to make informed decisions. You can then make your own decision whether or not veggies or grains are permissible for your dog’s diet.
The first study from 2011 found in Northeastern Naturalist, was attempting to identify a way to properly determine captive/escaped wolves vs wild wolves to clarify a possible need for regional wolf conservation projects. They used bone and hair samples of deceased animals to determine the carbon isotopes present. This would provide evidence of the type of diet they were eating or being fed. The kind of carbon isotopes found, told them what plant was in the diet the wolves were eating. This helped them determine if the animal in question was a “wild” wolf or an escaped “pet” wolf. Since many pet diets contain corn, this would help differentiate between the two. Corn vs wild plants naturally occurring in their diet.
Scientists were concerned that in some regions this test may be problematic due to there being more natural sources of the carbon isotope C4, which is also the indicator for corn. In the region they were testing, this was not a concern, but in other areas of the country if wolves were feeding off livestock fed primarily corn based diets or deer possibly eating corn from fields, C4 levels may be increased. They also analyzed three species of fruit (blueberry, blackberry and cranberry) in the area, for the research study as “many canids eat fruit in the fall”.
The implications of this study are that scientists, not concerned with diet or sources of food per say, were definitely concerned that wild canids DO eat plants.
The second study from 2013 found in the journal Nature was a genetic study. The study was being conducted to determine when dogs were domesticated and from what linage they descended, because it is an important episode in the history of human civilization. The study used sequenced genomes to evaluate support for proposed regions that were supposed to be sources of domestication.
On this genetic level they investigated the amylase gene family in dogs. Without amylase, an animal is able to eat vegetation and starches, but unable to process them internally to get nutrition from them. Finding the presence of amylase was considered most important, due to the sudden increased dietary starch they would have had in their diet, at the beginning of the domestication process.
Researchers found differences, across dog breeds and wolves, in the number of amylase genes that help digest starch. Amylase would have been critical to domestication, allowing early dogs living near human areas to more quickly adapt to an agricultural diet (scraps from people). Interestingly, while most breeds of dog had high numbers of amylase genes those not associated with agrarian societies like the Siberian husky and dingo, did not.
DNA research was being used not to prove that wolves or dogs had amylase genes, but to help determine possible time and place of domestication, looking at the increase of these genes and the timing in which it occurred.
Modern science at work, helps us in feeding our pets. This does not mean your dog can healthfully survive on a diet mainly of starch, no more than we could. It does however allow us to consider the possibility of a varied diet of meat, greens and starches, as not unnatural.
Northeastern Naturalist 2011, Vol 18, Number 3