Anyone who has ever owned a cat will immediately recognize the thorny "problem" of plant eating. This behavior is not so much a problem for the cat as for the plant-loving cat owner - just as long as the plant is not toxic. Toxic plants, like Easter lilies, Oleander and Dieffenbachia, shouldn't be around unless the owner can assure that the cat will never be able to reach them. Before addressing what to do to prevent plant eating, let consider why a carnivore like the cat would even want to spend his time eating plants. There are many theories on the subject, but none has gained favor.
Possible Reasons Why Cats Eat Plants
Plant eating may have some survival benefit to cats and thus be genetic. The purpose of the activity is thought to be to supply dietary fiber, which may or may not assist with certain digestive processes. Dietary fiber is obtained when cats eat the intestinal contents of small prey animals. Plant eating may have evolved to supplement this meager fiber supply in order to ensure adequate intake. In support of this notion, prey-eating cats in the wild take time out to eat grass so the behavior is not just confined to fiber-deprived domestic cats that dine on kibble and canned food.
One reason why fiber may be beneficial is as a laxative to assist with the passage of hairballs through the intestine. But, when consumed in large quantities, grass makes cats vomit, so it can also serve as a natural emetic. Regurgitation of hairballs following the consumption of grass should immediately relieve the cat, thus reinforcing the behavior.
It is also possible that cats eat some plants because they taste good or make them feel good. For example, plants like catnip contain materials that produce seemingly pleasurable effects. And even the leaves of the humble spider plant may contain a hallucinogen with opioid-like effects. It is said that chronic feasting upon the latter can dull your cat's wits.
How To Stop Plant Eating
Plant eating is a normal cat behavior that should be accepted and/or redirected appropriately by cat owners. It is only a problem for the cat where poisonous plants are consumed. While Poinsettias have a bad name, if consumed by the cat, they will probably only cause the cat to salivate. Their toxicity to cats and dogs has, in the past, been considerably overrated.
Other plants, however, like Easter lilies, Oleander, and Dieffenbachia may be true causes for concern. Easter lilies may trigger kidney failure; Oleander can cause cardiovascular problems; and Dieffenbachia species can cause tongue swelling and inflammation and sloughing of the wall of the intestinal tract. The list of plants that could cause problems is long but not all toxic plants are common houseplants or even attractive to cats.
In bringing a new plant into a house where there is a cat it is best to check the plant's potential toxicity first. Then, in light of the information you find you can consider whether to risk keeping the plant or where to place it so that the cat can't get at it. Non toxic plants, like most grasses, are obviously safest and some probably should be provided simply to accommodate your cat's plant eating desire and for enrichment of his environment.