There are a few "premixes" for dog food that are suitable for vegan dogs. These mixes usually contain dehydrated veggies, grains, and vitamins and minerals. You add protein and fat along with hot water to make a complete meal. Instead of adding meat, just use beans, lentils, etc. for protein and various vegetable-based oils for fat. It's always a good idea to rotate protein and fat sources. I'm sure there are others out there that are vegan-friendly, these are just the ones I've seen.
Veg-To-Bowl (100% GRAIN FREE)
Original Dog Food Mix (Wheat, Corn, and Soy Free)
Monzie's Organic Muesli (Wheat, Corn, and Soy Free)
Premixes are convenient and great for traveling (Just pack some dry premix, a can of beans and a little container of oil. Don't forget the can opener!).
Oh, yes, Sable says "Hi!"