There were a few things that I had heard and/or experienced about fruits
and vegetables for dogs.
On Broccolli and Cauliflower -- I had always thought that the best way to
give these veggies to them was cooked. That way, there is less absorbtion
of gas. But, I would assume that as with anything else, moderation in
quantity is called for.
On Carrots -- We have one dog who was living with her junior handler for
about the first year of her life. She had always shown a liking for
carrots as the young lady regularly gave them to her as treats. She has
been at our house for about four years now and still loves them as a treat.
Also, the hardness of the raw carrot has the same benefits as the eating
of dog cookies for the tartar on the teeth.
On Fruit -- We have fresh fruit quite often as nighttime snacks while
watching TV. The dogs love the apple and pear cores. My dogs have been
getting this as treats for many years and we had never had a problem with it.
Years ago, my wife used to make a "dog soup" with some veggies and rice to
use as a flavor additive to the dry kibble we fed them. Back then, we used
to use Blue Seal Ultra 27 for the show dogs and Natural 26 for the rest.
For the past six years, we have had the shows on National Competition (a
sled dog formula) and the others on Euk. I don't think they actually need
other things on the food, but we do have a few finnicky eaters and
sometimes have to add flavoring as an inducement to eat.