Cats are obligate carnivores. In 1982 Taurine an amino acid only present in meat, was found to be crucial for the healthy functioning of the cat. Taurine is vital for aspects of metabolism, eye sight, cardiac function, bile formation and reproduction. Cats are not able to synthesise sufficient taurine themselves and must have an adequate dietary supply. As taurine occurs almost solely in materials of animal origin, cats should not be fed on a purely vegetarian diet.
Dogs are omivores and can be fed a balanced vegetarian diet.