There are many benefits claimed for feeding raw food diets to cats, including improved immune function. Although 4% of U.S. cat owners feed raw diets as all or part of their cat’s diet, there are no published studies examining whether these diets are complete and balanced for feeding cats or whether immune function is improved in cats on a raw food diet. The goal of this study is to determine whether a commercially produced raw food diet and a homemade raw diet are nutritionally adequate for feedings kittens and whether these diets enhance immune function and improve digestibility. The outcomes to be measured include growth rate, feed efficiency, digestibility, and various blood and immune status parameters. The long term goal is to evaluate ways of improving feline immune function through diet.