I feed raw, and aside from the meat and bone they get a wide variety of veggies, which is almost like a supplement in itself. They get everything from beansprouts, to turnips, to yams, to dailan (a chinese green veggie), even taro root. If it's edible, they get it.
On top of that, they get plain yogurt several times a week, along with kelp, halibut oil, cayanne pepper, ginger, and apple cider vinegar added to their mash on meat or veg days.
I initially added flax meal, but Gage is allergic to flax. Once in a while I'll throw in some oatmeal or barley and just listen to him snore :roll: Aside from that my dogs' diet is grain free.