Mordy said:
Actually they do stil have the same digestive tract, which is the reason why they can (and most do) thrive on raw diets, but that doesn't mean they can't have health problems similar to those of humans, such as for example schnauzers can be prone to pancreatitis. Then there's also the variance of ratio of digestive tract to body size in different breeds (e.g. chihuahua vs. great dane), but nevertheless - anatomically they're still the same.
You are the nutrition expert here, and I am not about to debate that at all... But from what I have learned (and please correct me if I am wrong, I am always willing to learn).
The above, raisons, onions, chocolate and grapes can be considered harmful.
Way back when... when canines had to scavenge for food, they ate what they could, because they were pack animals and had too. They had to hunt and eat to survive.....
Now, present times..... dogs vary... They have been breed, over bred, mix-bred and so on.... since then, they have not only had/have "new" medical problems/issues, they also have allergies, skin disorders, etc... EVEN WITH the new medical advances.....
Most vets tell most people, not to feed chicken bones, or certain types of food, for various reasons.
Dogs have adapted to "common" diets... and we still have to give them Pepto Bismol at times...cottage cheese, rice and boiled chicken. To me, this does not sound like "our" dogs at this time and date have the same digestive function as their long ago relatives.
Time is change and change can bring on different issues....
Then again, this is just my own opinion.