Known in San Jose as ""the veterinarian who saves old animals with vitamins,"" Belfield (How to Have a Healthier Dog) here argues persuasively the merits of vitamin/ mineral supplements for cats. Such supplements fortify the immune system, making it better equipped to prevent and fight off disease. Commercial cat food isn't enough: it often lacks sufficient nutrients. One chapter is devoted entirely to the virtues of Vitamin C--universally omitted from cat food under the faulty assumption, Belfield emphatically states, that cats produce all they need. Cited are numerous cases where Vitamin C has neutralized toxins, slowed the aging process, acted as an analgesic, and (in mega doses) deactivated deadly viral diseases such as feline leukemia. Belfield extols the benefits of other vitamins and minerals, too, providing instructions on how much to give (and how to administer) to kittens and cats. Also explained is which specific vitamins are effective for which feline ailments (skin allergies, urinary blockages, tumors. . .). Well organized, and if short on statistical ""proof,"" generally common-sensical.