Dogs are not Omnivores — The Omnivore Lie
Because the dog is able to survive on plant-based foods and garbage scraps the erroneous assumption that dogs are omnivores has been propagated by pet food companies and councils sponsored by them. This is disingenuous as the dog’s ancestor the wolf, also eats plant-based foods and garbage scraps. HOWEVER the Wolf will only eat this way when there is a lack of prey and food is scarce. Basically, eating what it can in order to survive in famine like conditions.
A study of wolves in Western Iran where there is a low abundance of wild prey, together with the lack of an effective management of organic waste, found that this trophic plasticity allows wolves to persist in multiple human-dominated landscapes even in scenarios with low abundance of wild prey.
Wolves eat berries in the summer months, because berries can be acquired with little energy expenditure in the summer months when availability of mammalian prey is low. (Tremblay et al. 2001). During late spring and early summer (late May to mid‐Jul) in the GVE, wolves are primarily hunting and killing white‐tailed deer fawns and beavers (Gable et al. 2017a, 2018a). By mid‐to‐late summer (mid‐Jul to Aug), deer fawns are quick enough to evade wolves, and beavers rely more on aquatic vegetation (Severud et al. 2013. This period of reduced prey vulnerability coincides with a period of abundant wild berries. Though wild berries do not provide as much caloric value as mammalian meat (0.51 kcal/g vs. 1.87 kcal/g respectively; Gable et al. 2017b) and are likely less digestible for wolves than mammalian meat, their abundance and relatively low risk and energetic cost to obtain likely makes berries a valuable alternate food source for wolves.(Homkes et al).
No one has ever seen a wolf eat the stomach contents of their prey and this erroneous myth is purely anecdotal. “Contrary to popular belief, wolves do not consume the (partly fermented) vegetable matter in the rumen of ungulates. During removal, however, the rumen can be punctured, and its contents spilled of which some can be consumed along with other body tissues. Furthermore, the rumen lining and the intestinal wall can be consumed. Based on these studies reporting data on the foraging ecology, wolves can be considered true carnivores in their nature with vegetal matter being a minor to negligible component of their overall diet.” Guido Bosch , Esther A. Hagen-Plantinga ,Wouter H. Hendriks (a1) “
Just like the wolf, our dogs will eat whatever they can to survive. Dogs are facultative carnivores – occurring optionally in response to circumstances rather than by nature.
Recent data from researchers of the animal nutrition groups of Wageningen University and Utrecht University confirm that the ‘feast and famine’ lifestyle of wolves underlie the dog’s characteristic traits rather than an ancestral omnivorous diet.
During times of famine the wolf will eat what it can to survive and it is this characteristic that the dog has taken with it into domestication and with domestication the dog has the increased capacity for glycogen/starch digestion and for glucose uptake. However, even though this trait has developed over years of domestication the dog has more similarities to the cat than not. The authors Bosch, Hagen-Plantinga, & Hendriks, 2015 hypothesise that these ‘omnivorous’ traits, highlighted in blue, reﬂect the typical feast-or-famine lifestyle of the carnivorous dog’s ancestor, the wolf. Traits outlined in green and blue are functional for periods of feast and famine, respectively. Dogs share numerous traits with cats, shown in red. Capacities of traits shown in grey are the target over the course of domestication, dogs appear to have adapted to eating small amounts of starch and vegetation (Axelsson et al., 2013 (dietary_nutrient_profiles_of_wild_wolves_insights_for_optimal_dog_nutrition.pdf).