> Most wild dogs would eat almost exclusively fresh raw meat
Is that right? I understood most wild dogs eat a fair proportion of roots/berries and other herby stuff. A quick dig around:
"Unlike cats, dogs aren’t obligate carnivores. They can and do eat vegetable matter. Wild dogs will search for rotten fruit and will eat the semi-digested contents of their prey’s stomach. Some will dig up vegetables and eat grasses and herbs"
I'm not sure where that data is sourced from... Notice it's on the website of
a dog food company, who I suspect has an incentive to tell owners that the veg in the dog food is 'natural'.
I suspect if dogs do eat vegetables in the wild, it's only if they can't get enough meat, since their domestication has made them less good hunters. Their wild counterparts, grey wolves, don't seem to ever eat vegetation (except when sick).
Uncooked meat does not have near as many digestible calories density wise as cooked grains. Of course it would be a lot harder for them to become overweight, but the food cost would be tremendous. Remember that obligate carnivores that weigh a lot, like tigers, are incredibly expensive to feed.
"Our observation that mice fed cooked meat
retained higher body mass despite lesser intake (fresh- or dry-
weight basis) indicates that cooking increases the energy extracted
per gram of meat fed. This finding contrasts with the predictions of
conventional nutritional assays, which on the basis of the Atwater
system, return roughly equivalent metabolizable energy densities
for raw and cooked meat on a dry-weight basis (Table S1). The
problem with the Atwater system is that it ignores changes in di-
gestibility, costs of digestion, and costs of immune defense, all of
which are likely influenced by food processing. The result is nu-
tritional inaccuracy. For example, cooking is known to increase the
proportion of starch digested at the terminal ileum before access
by most gut bacteria (2). Starch that resists digestion in the small
intestine delivers only a proportion of its metabolizable energy to
the consumer, because the short-chain fatty acids produced during
bacterial fermentation of starch generate less ATP than the glu-
cose produced by starch hydrolysis in the small intestine. Addi-
tionally, the fatty acids are consumed as fuel for gut bacteria, and
there are further losses from the production of combustible gases
(40–42). Cooking, thus, increases the energetic value of starch to
an extent greater than is represented by the Atwater system. Such
differences between the calorie values determined by the Atwater
system and the physiological outcomes observed in this study are
relevant for the manipulation of diets to increased or decreased
caloric loading."
* Energetic consequences of thermal and nonthermal food processing Carmody, R. N., Weintraub, G. S., Wrangham, R. W., Proceedings of the National Academy of Sciences2011 / 11 Vol. 108; Iss. 48
Note that the 'Atwater' system is referring to the traditional method used to determine caloric content created in the 1890s which burns food and measures the heat obtained from it.
I apologize for the single source -- I believed that the science was far more settled on this issue than it appears to be. Regardless, I hope it proves informative for further research if you decide to pursue it.
Most wild dogs would eat almost exclusively fresh raw meat.
Whereas dog food tends to be dried meat with lots of corn as a filler. People wouldn't be able to afford 100% meat dogfood, because dogs eat a lot.