Some people. No dogs are not naturally going to attack a cornfield. They do however get nutrional value off of vegetables and they have systems that can digest vegetable matter. In other words their digestive system is set up similar to an omnivore, like that of a bear. They may prefer meat, but they can just as easily digest and get nutrition from non-meat products. I never said I'd prefer to have only starch in the food, as it is not good for anybody, but other vegetables are good for dogs. Cats on the other hand are carnivores who get little to no nutritional value off of eating vegetation. You don't see much cat food with beef, carrots and peas or chicken and rice do you. No you see seafood blend or chicken, turkey, and salmon. The only time you see rice is in a food that is made for cats is for those who have problems in the area of defication. Many dogs will actually steal veggies out of gardens if given the chance because they can eat them with no problems. Cats on the other hand will just eat the leaves off you houseplants and grass because it helps with upset stomachs or because some have strange taste, but they don't get any nutritional value from doing it.