Get Them Brussels Sprouts Outta Here!

There are people who take their food moralizing to extremes by not providing animal or animal-derived food to their pets -- including pets that have evolved to eat meat and have systems that are designed to do nothing else.

So you have the phenomenon of people who have cats insisting on making their cats "vegan" and feeding them food that comes only from plants. At first this may just seem silly to...well, anyone, I guess, who stops and thinks for a second. Cats aren't capable of making informed moral choices, so when they kill an animal and eat it, they are doing what they are designed to do in the same way a cow does what it is designed to do when it eats grass.

And if this idea of somehow retraining carnivores into becoming vegetarian were really practical, then why not start on the big cats as well? Any vegan who wants to convince me he's serious about his belief that all animals can be vegetarian needs to buy a lion and feed it carrots and lettuce. I'll spring for the casket, 'cause I think there won't be a whole lotta vegan left after Leo expresses his disinterest in the experiment and it won't cost me that much.

On a serious note, the attempt to restrict your average house Felis silvestris catus to a diet of leafy green things is actually harmful to it. Vegetables are indeed good for you, just like Mom said, but they lack an amino acid called taurine (OK, technically "2-aminoethanesulfonic acid," so you can see why we'll stick with taurine), which cats need in order to see. When their diets lack taurine, the cats undergo retinal degeneration, which after awhile becomes permanent.

Other animals and people need taurine, but they have the the ability to synthesize it from other amino acids because their diets have included vegetables, despite the best efforts of every seven-year-old who's ever lived. Cats, having eaten meat, the whole meat and nothing but the meat for most of their existence now, can't make their own taurine and need to have it in their diets, which means they have to eat meat -- 'cause that's where the taurine is.

Long-term taurine deficiency can cause enlarged hearts and other cardial problems, such as death. So Mr. Vegan's noble choice to be responsible for the death of no animals is directly responsible for the death of whichever animal happens to have the misfortune of living  -- or not living -- with him. Of course, the cat is more likely to die from some complication of malnutrition, as cats' famed finickiness is actually part of their digestive imperative to seek out foods they need and avoid foods they don't.

Which means that when cats stare at people who try to make them vegetarian or vegan, they're silently saying, "My stomach is smarter than your brain, primate. Guess opposable thumbs and walking on your hind legs ain't all they're cracked up to be, huh?"