Have you been told not to give your dog people food?
But you've probably also been told (more than once) to "eat your veggies" ... because they're good for you!
Fruits and vegetables aren't just good for you, they're good for your dog, too. Your dog benefits from eating spinach just like you.
It doesn't matter what kind of diet your dog eats.
Canned, kibble, or raw-fed dogs all benefit when you add fruits and veggies to their diet.