Banjo, For a dog and a cat to be a true carnivore, they would have to not eat plant and grass is a plant matter. I have seen dogs eat salad off the bowl and cats laying down nibbling on carrot sticks. You can eat grass, just the kind that does not cut your tongue. One day there will be a market for grass from the ground. I think in Japan they do eat some type of grass grown locally and are eaten by human consumption.
Dogs and cats are carnivores. There's no way to dispute such a fact. But human beings, that's a different story. They are omnivores by nature. What people may not know is that carnivores cannot develop atherosclerosis while we can. Why is that? Because we are not carnivores. Carnivores can take in a large amount of fat and cholesterol and not develop heart disease at all. It's how their bodies are designed. Herbivores cannot or they will develop heart diseases at an incredibly rapid rate.
A true example of an animal that eats plants exclusively would be I think, the whale shark or one of the shark species that are a ocean bottom plant eater. I am sure there are more animals on dry land that eat plants exclusively.
They are called herbivores. Our bodies are really much, much closer to these of herbivores than carnivores. Just do a little research on body digestion and how similar our bodies are to these of herbivores in comparison to carnivores but our teeth doesn't indicate that we are entirely plant eaters. After all, you don't see cows with fangs. That would be a bit of a scary sight though.
Most of the animals and human beings are somewhere in a mixture of eating meat and plants but Scientifically speaking, yes science needs to separate and differ between what animal's eating habits are like.
They are called omnivores. Bears is one of them.