Cat food
Cat food is food specifically formulated and designed for consumption by cats. During the 19th and early 20th centuries, cats in London were often fed horse meat sold by traders known as Cats' Meat Men or Women, who traveled designated routes serving households. The idea of specialized cat food came later than dog food, as cats were believed to be self-sufficient hunters. French writers in the 1800s criticized this notion, arguing that well-fed cats were more effective hunters. By the late 19th century, commercial cat food emerged, with companies like Spratt's producing ready-made products to replace boiled horse meat. Cats, as obligate carnivores, require animal protein for essential nutrients like taurine and arginine, which they cannot synthesize from plant-based sources.
Modern cat food is available in various forms, including dry kibble, wet canned food, raw diets, and specialized formulations for different health conditions. Regulations, such as those set by the Association of American Feed Control Officials, ensure that commercially available foods meet specific nutritional standards. Specialized diets cater to cats with conditions like chronic kidney disease, obesity, and gastrointestinal disorders, adjusting protein, fat, and fiber levels accordingly. Weight control diets often include fiber to promote satiety, while high-energy diets are formulated for kittens, pregnant cats, and recovering felines.
Alternative diets, such as grain-free, vegetarian, and raw food, have gained popularity, though they remain controversial. Grain-free diets replace traditional carbohydrates with ingredients like potatoes and peas but do not necessarily have lower carbohydrate content. Vegan and vegetarian diets have limited studies demonstrating their safety. Raw feeding mimics a natural prey diet but carries risks of bacterial contamination and nutritional imbalances. The pet food industry also has environmental implications, as high meat consumption increases pressure on livestock farming and fish stocks.
Nutritionally, cats require proteins, essential fatty acids, vitamins, and minerals to maintain their health. Deficiencies in nutrients like taurine, vitamin A, or arginine can lead to severe health problems. The inclusion of probiotics, fiber, and antioxidants supports digestive health, while certain vitamins like E and C help counteract oxidative stress. The pet food industry continues to evolve, balancing nutrition, sustainability, and consumer preferences while addressing emerging health concerns related to commercial diets.
History
During the 19th century and early 20th centuries, meat for cats and dogs in London, frequently horse meat, was sold from barrows by traders known as Cats' Meat Men or Women. Henry Mayhew estimated in London Labour and the London Poor that the total number of cats in London might be 300,000. Each cats' meat seller had a particular route and served a few hundred households, their approach marked by mewing cats.The idea of preparing specialized food for cats came later than dog food and dog biscuits. This was likely due to the idea that cats could readily fend for themselves. In 1837, a French writer critiqued this idea:
In 1844, another French writer,, expanded on this idea:
He goes on to say that it is all the more unreasonable to expect a cat to live from hunting in that cats take mice more for amusement than to eat: "A good cat takes many and eats few."
By 1876, Gordon Stables emphasized the need to give cats particular food:
In the same year, an advertisement for Spratt said that their cat food entirely superseded "the unwholesome practice of feeding on boiled horse flesh". And, in another book on cats, Stables recommended the company's food:
Spratt, which began by making dog biscuits, was the first commercial producer of ready-made cat food.
Natural diet
Cats are obligate carnivores—meaning, they are true carnivores and depend upon the nutrients present in animal flesh for their dietary needs in nature. Even domesticated cats can consume freshly killed meat from rodents, rabbits, amphibians, birds, reptiles and fish, whether through hunting or by having it provided by humans. The dietary needs of wild cats does not include any vegetable matter and consists solely of animal tissue. Whilst some plant matter is found in samples of the stomach content and faeces of cats the amount is negligible.Cats cannot synthesize some nutrients that are non-essential for humans and required for survival, including the amino acids taurine and arginine. Some of these nutrients are not found in plants and must be sourced from meat in the natural diet. Cats lack the specific physiology to extract nutrients efficiently from raw plant-based materials, and require a high protein diet.
Special to the cat's metabolism is the inability to convert carotenoids to vitamin A; inability to synthesise enough vitamin D; inability to synthesise niacin from tryptophan; inability to synthesise cysteine, citrulline, and methionine; and an intolerance to glutamic acid.
Packaging and labeling
In the United States, cat food using the label "complete and balanced" is required to meet standards that have been established by the Association of American Feed Control Officials by either meeting a nutrient profile or passing a feeding trial. Cat Food Nutrient Profiles were established in 1992 and updated in 2014 by the AAFCO's Feline Nutrition Expert Subcommittee. The updated profiles replaced the previous recommendations set by the National Research Council. Certain manufacturers label their products with terms such as premium, ultra premium, natural and holistic. Such terms currently have no legal definitions. However, "While most of the food supplied comes from within the US, the FDA ensures that standards are met within our borders even when components come from countries with less stringent levels of safety or label integrity."Gastrointestinal health
The gastrointestinal tract is the source of nutrient absorption, making it integral to overall health. Research shows fiber, prebiotics, probiotics, antioxidants and fatty acids are important in maintaining gastrointestinal health.To achieve optimal cellular health and to maintain a healthy microbiome, proper nutrition is necessary.
Cats with gastrointestinal diseases must consume an easily digestible diet with the appropriate nutrients provided by easily digestible ingredients and in the correct ratio which is recommended to be fed in small portions frequently throughout the day, so as not to overwhelm the digestive system.
It is also important for fat to be digestible because too much undigested fat that reaches the end of the digestive tract has the possibility of being fermented and can worsen the symptoms of GIT disease and induce other reactions like diarrhea.
It has also been suggested that cats should eat diets tailored to the section of the GIT that is diseased.
When certain nutrients like fructooligosaccharides are included in the diet, the microbiome and fatty acid content are often changed for the better. An example is less branched-chain fatty acids are produced and more short-chain fatty acids are produced.
FOS can also impact production of other fatty acids.
Malnutrition
Malnutrition can be a problem for cats fed non-conventional diets. Cats fed exclusively on raw, freshwater fish can develop a thiamine deficiency. Those fed exclusively on liver may develop vitamin A toxicity. Also, homemade diets, either 'organic', 'natural', or 'vegetarian' may contain excessive protein and phosphorus while being deficient in calcium, vitamin E, and microminerals such as copper, zinc, and potassium. Energy density must also be maintained relative to the other nutrients. When vegetable oil is used to maintain the energy balance, cats may not find the food as palatable, causing less food to be eaten.Commercial foods
Most store-bought cat food comes in either dry form, also known in the US as kibble, or wet form. Some manufacturers sell frozen raw diets and premix products to cater to owners who feed raw.Dry
Dry food is generally made by extrusion cooking under high heat and pressure. Approximately 95% of dry pet foods are extruded. During this process, the meat is first ground up, cooked under very high heat, and processed so it becomes a powder. The powder is fed into a massive mixer. In the mixer, additional supplements are added; then it's cooked again at very high heat to turn it into a dough, which is molded in the shape of kibble, and baked. At this point, it no longer smells like meat. Fat may be sprayed on the food afterwards to increase palatability, as well as other minor ingredients, such as heat-sensitive vitamins, which would be destroyed in the extrusion process. Dry food is most often packed in multi-wall paper bags, sometimes with a plastic film layer; similar bag styles with film laminates or coextrusions are also used.Dry foods contain high amounts of carbohydrates in order to maintain their shape and structure. Concerns have been raised that there is some association between the carbohydrate content and risk of obesity and type 2 diabetes in felines.