We’re referring to the most noticeable teeth in the cat’s mouth—the “fangs,” two on the top, two on the bottom. Biologists referred to these sharp, prominent teeth as “canines,” regardless of what animal has them (including humans).
They are the “rippers” in the cat’s mouth that not only do the serious business of tearing large bits of food, but also do the equally serious work of biting an attacker. As in most animals, the cat’s canines are pointed slightly inward, so whatever they fasten to—food or enemy—finds it difficult to escape.