“Do cats need grass?” was the question posed to me by a reporter for the New York Times.
Certainly those of us with houseplants and cats know our feline companions can do a good deal of damage snacking in the windowsill garden. My beloved cat, Symba, ascribed to the Morticia Addams school of floral design when it came to roses. He would gently behead every flower until the vase contained only stems and the floor below was littered with blossoms.
From a nutritional standpoint, cats do not have a nutritional requirement for the carbohydrates contained in grass. They are obligate carnivores, meaning they are biologically designed to consume, digest and obtain all their nutrients from meat. Cats do not have the flat wide teeth for chewing grass like cows do; the feline dentition had evolved to efficiently eat meat, not chew grass. Cats have a very short digestive tract as meat is more readily digested than grass. Unique to the cat is their requirement for the amino acids, arginine and taurine, which are found only in meat.
Just because they don’t have a requirement for carbohydrates doesn’t mean they can’t utilize the nutrients provided by carbohydrates. Most commercial cat foods contain some carbohydrate source helping to create a balanced diet for your cat. But cats don’t need the carbohydrates or cat grass for that matter.
Even if they don’t need a cat salad, some cats really like to eat plants. No one knows exactly why, but we can speculate. Since cats do typically not digest grass, they often vomit it back up with a hairball or two. The theory is the cat uses the grass to rid itself of hairballs. But not all cats that eat grass vomit.
The next theory is cats consume grass because they have a nutritional deficiency. In my clinical practice at the Animal Medical Center, nutritional deficiencies are rare because cat foods are highly researched and government regulated to assure cat owners they are feeding a complete and balanced diet. I actually think cats may simply like to chew on plants because they taste good or because they are fun to eat. My plant-eating cat especially liked spider plants and would bat at the leaves and then pounce on the moving ones before he ate them level with the dirt in the pot.
So if your cat craves a salad, go ahead and feed her one. Just be sure it is a safe salad. Certain houseplants such as lilies, amaryllis and crocus can cause kidney failure in cats. More on plants toxic to pet can be found on the Animal Poison Control website.