By definition, dogs are not obligate carnivores. An obligate carnivore can only derive the their nutritional need through meat, they simply cannot process vegetable, fruits, grains, etc. well enough to derive any nutritional value from them. This is simply not true for dogs. Dogs are opportunistic carnivores. They process meat, organs, bone, etc. better than they can process vegetable matter, but they do derive nutrients from vegetables and other non-meat food sources well enough that they can survive without meat, thus they are not obligate carnivores like cats are.