Cats are obligate carnivores. This means they are intended to have their nutritional needs met by the consumption of other animals. There is very little nutritional value for cats in plant-based food sources; in fact, physiologically, it is hard for their systems to effectively break down and utilize the nutrients in plant-based ingredients. As such, in a perfect world, they should have no grains at all in their food.
This means canned food is vastly preferable to dry kibble—kibble is convenient, but it is also, by its very nature, a far less nutritionally complete package. When it comes to canned food, guardians must always remember to carefully read food labels. A quality animal-based (meat) protein source should be the first ingredient listed on the food label, indicating it is that product's primary ingredient. Avoid foods that list as their first ingredient anything referred to as a "byproduct," or worse, grains like wheat, corn or rice.
Lisa Ward is a regular contributor to Angel Tales, the magazine of PAWS Chicago, and a PAWS volunteer. This article was originally published in the Spring/Summer 2007 issue of Angel Tales.