According to a recent article on www.examiner.com , even vegans say that cats need at least some meat in their diets, despite the recent article in The New York Times suggesting cats should stick to a vegan diet to protect fish.
The American Society for the Prevention of Cruelty to Animals takes the position that felines require a meat-based diet, and websites such as www.vegancats.com and www.essentialvegetarian.com agree that cats need some meat.
Of particular concern is that cats are unable to synthesize the essential amino acid taurine, and so must get it through their diets. Taurine occurs naturally only in meat, and a deficiency can result in blindness and even death for a cat, according to the article.