I eat what my parents raised me on (now a pesco-vegetarian diet).
My stomach has adjusted to that.
In fear of being ill (I have quite a sensitive immune system) I would not try non-human food.
Even my mom's dog and cats seem to prefer human food.
I recall that I did try a dog biscuit once when I was younger and for something given to a carnivorously inclined animal it sure tasted more spicy than meaty... And wet meat is just seemingly... Low quality to me.
Really, meat for animals should/would be the same as meat for humans, because, after all, meat in its rawest form is fundamentally from a dead creature.
As for vegetation, I have had the urge to eat grass for idk what reason (I mean I'm a therian to carnivorous species), I found it quite bitter.