Dogs are not obligate carnivores like cats are. Dogs can and have subsisted on "vegetarian" diets but that's a far cry from their optimal diet. This vegan diet for a dog really annoys me.
My three dogs get raw meat, organs and bones and as long as I can afford it, that is all they'll eat. After a lot of research I found this diet for my Dalmatian back in 2010 when she was about 12 and I was able to help her regain her vitality for a good three more years before she just couldn't go on anymore.
Seeing my Dalmatian transform like that gave me all the proof I needed.