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 non-human animals is a by-product 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 percent of the world's pet-food market, which in 2007 amounted to US$ 45.12 billion for cats and dogs alone.

Cat and dog food sales exceeded £1.4 billion in the United Kingdom and US$14.3 billion in the United States in 2005.[4] In 2006 the value of the UK pet food market rose to just over £1.6 billion. The leading exporters of pet food for 2004 were France ($993 million), United States ($786 million) and the Netherlands ($511 million). while the leading importers were Japan ($718 million), Germany ($617 million) and the UK ($563 million).

Prepared foods and some raw ingredients may be toxic for animals and care should be taken when feeding animals left-over food. It is known that the following foods are potentially unsafe for cats and dogs:

• Chocolate, coffee-based products and soft drinks
• Raisins and grapes
• Canned tuna
• Macadamia nuts
• Onions and garlic

Generally cooked and marinated foods should be avoided as well as sauces and gravies which may contain ingredients that although well tolerated by humans, may be toxic to animals.