If Lions and Tigers Eat Meat, Why is My Cat Eating Cereal (kibble)?
All living cats track back to a pantherlike predator that lived in Southeast Asia 10.8 Million years ago. The big cats (lions, tigers, leopards, pumas, etc.), were the first to branch off, and house cats were very late in the evolution of Felidae, not branching out until only 3 ½ Million years ago. Then only about 10,000 years ago was a small wildcat species from Asia first domesticated – leading to your house cat. The one thing that every species over that 10.8 Million years share, however, is that they are an Obligate Carnivore. All cats (members of the suborder Feloidea) are strict carnivores, which means they have evolved unique anatomic, physiologic, metabolic and behavioral adaptations consistent with eating a strictly carnivorous diet. So your domesticated cat (Felis catus) has a physiology that can only eat meat.
Like other Carnivorans (like dogs and wolves), they share a particular trait found in no other mammals, special, bladelike teeth called carnassials. Whether you look at the lion on the left or the house cat on the right, you can see their teeth are only sharp and pointy, with fangs up front and ‘meat scissors’ in the back.
When carnivorans use their back teeth to bite, these elongated blades shear past each other, slicing like scissors. This ability to shred meat allows them to swallow and digest their food more easily. Look at your teeth in the mirror: straight, even teeth up front, and in the back you have flat molars for grinding up plant matter. Look in your cat’s mouth and you immediately see up front fangs on top and bottom. In the back you won’t see flat molars like we have, but carnassial teeth for shearing raw meat into pieces small enough to swallow.
Why do you think your cat still hunts birds and mice? They are a predator and a carnivore the not only craves, but desperately needs raw meat to thrive. Obligate or "true" carnivores are animals whose diet requires nutrients found only in animal flesh. Specifically, cats have high protein requirements and their metabolisms are unable to synthesize essential nutrients such as retinol, arginine, taurine, and arachidonic acid. The only way to get these nutrients is by consuming flesh.