Pet food

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".[1]

In 2018, the world pet food market was valued at US$87.08 billion and is projected to grow to US$113.2 billion by the year 2024.[2] The pet food market is dominated by five major companies, as of 2019: Mars, Inc., Nestle Purina Petcare, J. M. Smucker, Hill's Pet Nutrition, Inc. (owned by Colgate-Palmolive), and Blue Buffalo Co. Ltd (owned by General Mills).[2]

Industry
In the United States, pet-food sales in 2016 reached an all-time high of $28.23 billion.[3] Mars is the leading company in the pet food industry, making about $17 billion annually in pet-care products.[4] Online sales of pet food are increasing and contributing to this growth. Online sales in the US increased 15 percent in 2015.[5] Worldwide, the compound annual growth rate of pet food purchased online was more than 25% between 2013–2018.[6] As of 2015 the US leads the world in pet-food spending.[7]

Formulations of mainstream commercial pet foods are generally based on nutrition research and many manufacturers undertake animal nutrition studies. For instance, Mars, Incorporated funds the Waltham Centre for Pet Nutrition, which undertakes scientific research into pet nutrition and wellbeing, sharing its findings in publicly available peer-reviewed journals.

Impact
Given the carnivorous dietary habits of many pets (especially cats and dogs), involving the consumption of an estimated fifth of the world's meat and fish, the impact of pet-food production on carbon footprints and on climate change becomes an issue.[8]

Fish food
Main article: Fish food
Fish foods normally contain macronutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish exclusively prepared foods that most commonly are produced in flake, pellet or tablet form.[9] Pelleted forms, some of which sink rapidly, are often used for larger fish or bottom-feeding species such as loaches or catfish.[10] Some fish foods also contain additives, such as beta carotene or sex hormones, to artificially enhance the color of ornamental fish.

Bird food

Bushtits eating suet from a bird feeder
Main article: Bird food
Bird foods are used both in birdfeeders and to feed pet birds. It typically consist of a variety of seeds. However, not all birds eat seeds. Nectar (essentially sugar water) attracts hummingbirds.[11]

Cat food

Cat with a bowl of pelleted cat food.
Main article: Cat food
Cats are obligate carnivores, though most commercial cat food contains both animal and plant material supplemented with vitamins, minerals and other nutrients. Cat food is formulated to address the specific nutritional requirements of cats, in particular containing the amino acid taurine, as cats cannot thrive on taurine-deficient food.[12] Optimal levels of taurine for cat food have been established by the Waltham Centre for Pet Nutrition.[13]

Dog food
Main article: Dog food
Recommendations differ on what diet is best for dogs. Some people argue dogs have thrived on leftovers and scraps from their human owners for thousands of years, and commercial dog foods (which have only been available for the past century) contain poor-quality meats, additives, and other ingredients dogs should not ingest, or that commercial dog food is not nutritionally sufficient for their dogs. However, many commercial brands are formulated using insights gained from scientific nutritional studies[14] and there is no reliable peer-reviewed evidence that domestic options are superior. Most store-bought pet food comes in either dry form, also known as kibble, or wet, canned form.

Raw feeding
Main article: Raw feeding
Raw feeding is the practice of feeding domestic dogs, cats and other animals a diet consisting primarily of uncooked meat, edible bones, and organs. dry dog food used to formulate raw diets can vary. Some pet owners choose to make home-made raw diets to feed their animals but commercial raw food diets are also available.

The practice of feeding raw diets has raised some concerns due to the risk of food borne illnesses, zoonosis and nutritional imbalances.[15] People who feed their dogs raw food do so for a multitude of reasons, including but not limited to: culture, beliefs surrounding health, nutrition and what is perceived to be more natural for their pets.[16] Feeding raw food can be perceived as allowing the pet to stay in touch with their wild, carnivorous ancestry.[16] The raw food movement has occurred in parallel to the change in human food trends for more natural and organic products.[17]

Feeding human foods to animals
Prepared foods and some raw ingredients may be toxic for animals, and care should be taken when feeding animals leftover food. It is known that the following foods are potentially unsafe for cats, dogs and pigs:

Chocolate, coffee-based products and soft drinks[18][19]
Raisins and grapes[18][19]
Macadamia nuts[18][19]
Garlic (in large doses) and onions[18]
Alcohol[19]
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. Xylitol, an alternative sweetener found in chewing gum and baked goods designed for diabetics, is highly toxic to cats, dogs, and ferrets.[20][21]

Labeling and regulation
United States