Dogs have been classified as omnivores in the scientific and public domain. The classification was based on the dog’s digestive and metabolic traits that differ from the carnivorous cat and resemble those omnivores like pigs and rats. Researchers of the animal nutrition groups of Wageningen University and Utrecht University have published their research in which they argue that a ‘feast and famine’ lifestyle of wolves underlie the dog’s characteristic traits rather than an ancestral omnivorous diet.
Domestic dogs diverged from grey wolves between 13 000 and 17 000 years ago when food waste from human settlements provided a new niche. Recent data showed that the domestication process only affected the ability to digest and utilise starch, i.e. other digestive and metabolic traits did not change over time in dogs. In order to gain insight in the nutritional background of dogs, the researchers studied the foraging ecology of wild wolves, closest free-living ancestor of dogs, and calculated nutrient profiles of fifty diets reported in the literature.
Data on the feeding ecology of wolves indicate that wolves are true carnivores consuming a negligible amount of vegetal matter. Wolves can experience prolonged times of famine during low prey availability while, after a successful hunt, the intake of foods and nutrients can be excessive. As a result of a ‘feast and famine’ lifestyle, wolves need to cope with a highly variable nutrient intake requiring an adaptable metabolism, which is still functional in our modern-day dogs.
The researchers also compared the nutritive characteristics of the wolf diet with that of commercial foods. Several aspects were identified that may pose physiological and metabolic challenges in dogs. The present study provides new insights into dog nutrition and contributes to the ongoing optimisation of foods for pet dogs.
The study has been published in the British Journal of Nutrition and is available via this link.