I wish vegetarian pets were as endearing as cats and dogs. To kill a cow or lamb or fish to feed a cat or dog is crazy.
You might look into advocating for animal welfare as opposed to animal rights. Good luck with your studies.
Carolyn: You can have your veggie cake & eat it too! It’s easy to keep dogs vegan – mine have lived to ripe old ages on vegan kibble. Cats, too, even though some say they can’t. See the book Obligate Carnivore for more details.