Asked by: Maria Sellick, Southampton
Dogs can survive on a vegetarian diet, but cats need meat, or a lot of additives to compensate. Among these are the amino acid taurine, not found in plants, and vitamin A, which dogs can manufacture from carotenoids found in plants, but which cats must get from the meat of animals that have done the manufacturing for them.
Cats are sensitive to deficiency of the amino acid arginine, and need the high protein levels found in meat to get enough. Dogs can become vegetarians, but cats are definitely carnivores.