Pet food is plant or animal material intended for consumption by pets. Typically sold in pet stores and supermarkets, it is usually specific to the type of animal, such as dog food or cat food. Most meat used for nonhuman animals is a byproduct of the human food industry, and is not regarded as "human grade".Four companies—Procter & Gamble, Nestlé, Mars, and Colgate-Palmolive—are thought to control 80% of the world's pet-food market, which in 2007 amounted to US$ 45.12 billion for cats and dogs alone.