The invention and skillful promotion of pet food quickly made it an accepted item on the American grocery list. The first commercial dog food was marketed in the United States in the 1870s; the first cat food appeared in the 1890s. Convenience, decreasing cost, new information on animal nutrition, and marketing savvy succeeded in bringing packaged pet food into more American households. Despite the Great Depression, purchases of canned pet food increased to $100 million in the 1930s. The federal government began regulating the nutritional content of pet food out of concern over human consumption. By the 1950s, pet food was yet another convenience food.

Cat Food Becomes Popular - Consumers were slower to adopt special food for cats than for dogs, and at first many canned foods were labeled for both dogs and cats. Producers of canned fish, however, realized that they could package the parts that people wouldn’t eat as cat food. The first brand of cat food that enjoyed aggressive national marketing was Puss’N’Boots, which was produced by the packers of Starkist Tuna. Cat food’s wide acceptance by the 1960s signaled that they status of cats as valued pets had changed.

      
Puss 'n Boots and Rival Advertisements, 1940s

Other pet foods - Other commercial pet foods appeared for sale gradually, as owners demanded the convenience of buying food where they purchased their animals and equipment. Commercial goldfish foods were sold as early as 1881. Some companies found profit in packaging mixtures of seeds and pellets in manageable quantities for small animals. Today, scores of small companies still manufacture and package special foods for caged and exotic animals, often selling their products over the web.

Spratt's Natural Aquarium Fish Food, 1920s