On the topic of feeding, there is an item worthy of reading.  I feed raw (with some grain-free kibble for supplement) and this article is for those who feed only kibble.  My dogs get raw and cooked vegetables most every day.  They love the core and spines of leafy greens, they also love beans, carrots, and almost all salad items, (no onions!).  They don't mind vinegar and oil dressing but your mileage may vary!

Check out this blog for more:
Rodney Habib - Pet Nutrition Blogger