By T.J. Dunn, Jr., DVM
In so many obvious ways, cats look, act, react, and respond differently than dogs. What is more difficult to see, however, is the metabolic and chemical differences between the two. Here are just a few of those amazing variations, and the reasons why you should pay close attention to what’s in your cat’s food.
The cat is considered by scientists to be a strict carnivore, while the dog is considered to be an omnivore. Both species are in the Class Mammalia and the Order Carnivora, but here’s the difference: Cat’s cannot sustain its life unless it consumes meat in some form. Dogs, however, are able to survive on plant material alone - they do not have to consume meat. But always keep in mind that dogs do best and, by nature, are primarily meat-eaters.
Taurine, an amino acid, is important for healthy the functioning of the heart, retina, bile fluid and certain aspects of reproduction. However, unlike in dogs, cats must eat preformed Taurine. That is why cat food must contain some source of Taurine, and in a proper amount.
Also called retinol, Vitamin A is required at the cellular level by both cats and dogs. Cats process little or no enzymes that will break down the plant-produced carotenoids. They must eat preformed active Vitamin A (that is, Vitamin A that already has been converted from carotenoids to its active form). Dogs, meanwhile, have enzymes in the lining of the intestine that can break down plant carotenoids and convert these into active Vitamin A.
A building block for proteins, Arginine is a vital amino acid for the body’s. Cats are extremely sensitive to even a single meal deficient in Arginine, and they are unable to make their own Arginine within their chemical factory. Dogs meanwhile, are not very sensitive to low levels of Arginine in their diets, and they produce enzymes internally that can aid production of Arginine.
If a dog eats enough proper fats, his body can produce Arachidonic acid. Cats, meanwhile, cannot produce this acid due to their liver’s inability to convert linoleic acid into Arachidonic acid.
So there you have it. The next time you admire a cat's unique personality and behavior, and watch the way they egocentrically carry themselves for anyone to see, remember ... hidden beneath that furry skin is another unique and vast universe. You can't see it, but it's there, silently following the rules of nature to sustain our unique and valued feline friends. And it's that complex chemical cosmos, working it's fantastic magic that prompts us cat lovers to say, truly ... cats are different!