Cat food edit extracted from Wikipedia, the Free Encyclopedia (using Wikipedia Reflection Script)

Cat with a bowl of dry cat food

Cat food is formulated to address the specific nutritional requirements of cats. Although cats are obligate carnivores, most commercial cat food contains both animal and plant material, supplemented with vitamins, minerals and other nutrients. An important nutrient is the amino acid derivative taurine, as cats cannot synthesize the compound. Cats fed a taurine-deficient dog food may develop retinal degeneration and go blind, for example.¹

Commercial cat food

Cat food for sale at an Istanbul animal market

Most store-bought cat food comes in either dry form, also known as kibble, or wet canned form. Some manufacturers sell frozen raw diets and premix products to cater to owners who feed raw.

Dry food

Dry (Extruded) cat food example

Dry food (8-10% moisture) is generally made by extrusion cooking under high heat and pressure. It may then be sprayed with fat to increase palatability and other ingredients to complete its composition.

Major brand-name dry cat food manufacturers often use primarily grain-based ingredients with animal protein by-products or animal digest to cut cost. Higher end foods offered as 'premium', 'natural' or 'holistic' formulas contains less or no grains and a higher percentage of animal protein. However, grain-free dry diets still contain carbohydrates, from sources such as potato or tapioca as the starch in those ingredients is needed to allow the kibble to hold its shape. Cats have no metabolic need for carbohydrates as the feline system prefers to create glucose from protein.²

Dry cat food has an advantage over wet in convenience and price - besides usually being significantly cheaper, dry cat food can also be left out for the cat to eat at will over the course of several days; whereas, canned or raw cat food spoils or becomes unappetizing after several hours. It should be noted, however, that even dry food, since it is sprayed with fats as noted above, becomes rancid and stale as it oxidizes. Using a free feeding practice can also contribute to overeating, and ultimately obesity.³

Dry food is recommended by some based on the idea that cats break apart dry foods with their teeth, which causes the food to scrape off dental calculus. The degree of benefit this provides has been disputed in recent years.⁴

Since the occurrence of BSE infection through contaminated meat and bone meal, the use of meat meal in pet foods has been prohibited in parts of the world (e.g. Japan and France) but is still common practice in other parts (e.g. USA).^{citation needed} Comparative studies conducted by Japanese researchers have shown that meat meal is superior to the other protein meal sources in terms of dry-matter digestibility and nutritional value for cats, while corn gluten meal is the least nutritional.⁵⁶⁷

The same studies showed that cats fed with these dry food diets excreted alkaline urine. Urine pH has been implicated in the formation of struvite crystals in feline urolithiasis, and many dry food manufacturers address this by adding urine-acidifying ingredients to their food. However, this practice may lead to the formation of calcium oxalate stones, therefore water intake rather than urine pH appears to be the most crucial factor for the prevention and treatment of feline stones.⁸

Wet food

Wet (Canned) cat food example (Fish flakes in jelly)

Canned or wet food (75-78% moisture) generally comes in common can sizes of 3 oz (85 g), 5.5 oz (156 g), and 13 oz (369 g). It is also sold in foil pouch form by some manufacturers.

Owners and veterinarians who recommend a diet consisting largely or entirely of canned, homemade or raw cat food point to higher water content of such food and the increased total water consumption in comparison to a dry food diet as an important health benefit. Wet food also generally contains significantly less grain and other carbohydrate material. Many foods are made with fish however and excessive consumption of fish (which contains high levels of unsaturated fatty acids) can cause yellow fat disease.⁹ In comparison to dry food, canned food is thought to either help treat or noticeably reduce the likelihood of numerous health issues including urinary tract disorders¹⁰¹¹, diabetes, chronic renal failure¹², constipation (sometimes leading to megacolon), and obesity.^{citation needed}

Canned cat foods in pop-top containers may play a role in the development of hyperthyroidism in cats¹³. This may be due to bisphenol A used in the pop-top can coating leaching into the food.¹⁴

Prescription food

Prescription foods for specific disease such as feline lower urinary tract disease and chronic renal failure are available through a vet or pet pharmacy.

Homemade Food

Further information: Raw feeding

Many pet owners feed cats homemade diets. These diets generally consist of some form of cooked or raw meat, bone, vegetables, taurine supplements, and other multivitamin supplements.

Vegetarian or vegan food

Vegetarian or vegan cat food has been available for many years, and is targeted primarily at vegan and vegetarian pet owners. While a small percentage of owners choose such a diet based on its perceived health benefits, the majority do so due to ethical concerns.¹⁵ Cats are obligate carnivores and require nutrients (including arginine, taurine, arachidonic acid, vitamin A, vitamin B12 and niacin) found in meat sources that cannot be obtained in sufficient amount in plant sources. According to the National Research Council, "unsupplemented vegetarian diets can result in harmful deficiencies of certain essential amino acids, fatty acids, and vitamins." ¹⁶ Vegetarian pet food companies attempt to correct these deficiencies by supplementing their products with synthetically produced nutrients.

Organizations that advocate vegan or vegetarian diets for people have split opinions regarding vegetarian or vegan cat food. The International Vegetarian Union¹⁷, the Vegan Society¹⁸ and Peta¹⁹ are some of the organizations that support a vegan or vegetarian diet for cats. On the other hand, the Vegetarian Society suggests people "consider carefully" and that many cats will not adjust to a vegetarian diet. They provide a list of necessary nutrients that will need to be supplemented with a recommendation to consult a veterinarian or animal nutritionist for those who want to try.²⁰ The Animal Protection Institute also does not recommend a vegetarian diet for cats and cautions that dietary deficiencies may take months or years to develop and may be untreatable. They do not recommend relying on supplements because they may not contain necessary co-factors and enzymes and have not been studied for long term implications.²¹ The animal welfare organization American Society for the Prevention of Cruelty to Animals, although suggesting a supplemented vegetarian diet for dogs,²² recommends against a vegetarian and vegan diets for cats.²³

One study evaluated cats whose owners were knowledgeable about vegetarian cat diets and had self-selected to feed commercial and/or homemade vegetarian diets.¹⁵ Cobalamin (vitamin B12) and taurine, two nutrients lacking in vegetarian food, was tested for. The study found that all the cats had serum cobalamin levels within the reference range but 3 of 17 cats had serum taurine values below the reference range. While low blood taurine level is indicative of long-term deficiency, the values were described as "marginal, but... not clinically deficient".

Even when adequately supplemented, vegetarian diets may present other risks, such as urine acidity problems. While there are anecdotal reports linking a vegetarian diet with urinary tract problems, no documented case report or study exist.¹⁵ One vegan cat food manufacturer has stated that "because of the relative acidity of meat to vegetable protein, many vegan cats suffer from [Urinary tract problems]."²⁴ A survey done during the above study showed that a quarter of respondents perceive feline lower urinary tract disease as a health risk of feeding a vegetarian diet.¹⁵

A few vegetarian cat food brands are labeled by their manufacturers as meeting AAFCO's Cat Food Nutrient Profile while other manufacturers recommend their products to be supplemented and not used as a standalone. A 2004 study evaluated two commercial pet foods for nutritional adequacy;Vegecat KibbleMix supplement and Evolution canned diet for adult cats. The study concluded that these two foods, counter to labeling claims, had multiple nutritional inadequacies when compared against the AAFCO minimal nutrient profile for cat diets. The authors recommended that these vegan diets should not be used as a sole source of nutrition for cats.²⁵

In response, Evolution Diet denied that their product is nutritionally inadequate, citing the "ten to twenty thousand healthy and long living dogs, cats and ferrets living on the Evolution Diet" as an example. They attribute the discrepancy as a likely formulation error. In an apologetic reply, the manufacturer of Vegecat attributed the test results to a manufacturing error during the mixing process and an inaccurate nutrient profile of a food yeast, and asserted they were taking steps to correct the problems.²⁶

Labeling

Further information: Pet food#Labeling and regulation

In the United States, cat foods labeled as "complete and balanced" must meet standards established by the Association of American Feed Control Officials (AAFCO) either by meeting a nutrient profile or by passing a feeding trial. Cat Food Nutrient Profiles were established in 1992 and updated in 1995 by the AAFCO's Feline Nutrition Expert Subcommittee. The updated profiles replaced the previous recommendations set by the National Research Council(NRC).

Critics^who? argue that due to the limitations of the trial and the gaps in knowledge within animal nutrition science, the term "complete and balanced" are inaccurate and even deceptive. An AAFCO panel expert has stated that "although the AAFCO profiles are better than nothing, they provide false securities. "²⁷

Certain manufacturers label their products with terms such as premium, ultra premium, natural and holistic. Such terms currently have no legal definitions.

Nutrients and functions

Vitamins are organic compounds that take part in a wide range of metabolic activities. Vitamin deficiencies can lead to widely ranging clinical abnormalities that reflect the diversity of their metabolic roles. Twelve minerals are known to be essential nutrients for cats. Calcium and phosphorus are crucial to strong bones and teeth. Cats need other minerals, such as magnesium, potassium, and sodium, for nerve impulse transmission, muscle contraction, and cell signaling. Many minerals only present in minute amounts in the body, including selenium, copper, and molybdenum, act as helpers in a wide variety of enzymatic reactions.²⁸

The table below lists the AAFCO nutritional profiles for cat foods along with the roles of vitamins and minerals in cat nutrition according to the National Research Council.

Diet and disease

Food allergy

Food allergy is a non-seasonal disease with skin and/or gastrointestinal disorders. The main complaint is Pruritus, which is usually resistant to treatment by steroidal anti-inflammatory drugs. The exact prevalence of food allergy in cats remains unknown. There is no breed, sex or age predilection, although some breeds are commonly affected. Before the onset of clinical signs, the animals have been fed the offending food components for at least two years, although some animals are less than a year old. In 20 to 30% of the cases, cats have concurrent allergic diseases (atopy / flea-allergic dermatitis). A reliable diagnosis can only be made with dietary elimination-challenge trials. Provocation testing is necessary for the identification of the causative food component(s). Therapy consists of avoiding the offending food component(s).³⁰

Malnutrition

Cats fed exclusively on raw, freshwater fish can develop a thiamine deficiency. Those fed exclusively on liver may develop vitamin A toxicity. Malnutrition has been seen in cats fed "natural", "organic", or "vegetarian" diets produced by owners with good intentions, and most published recipes have been only crudely balanced (by computer) using nutrient averages. Because the palatability, digestibility, and safety of these recipes have not been adequately or scientifically tested, it is difficult to characterize all of these homemade diets. Generally, most formulations contain excessive protein and phosphorus and are deficient in calcium, vitamin E, and microminerals such as copper, zinc, and potassium. Also, the energy density of these diets may be unbalanced relative to the other nutrients. Commonly used meat and carbohydrate ingredients contain more phosphorus than calcium. Homemade feline diets that are not actually deficient in fat or energy usually contain a vegetable oil that cats do not find palatable; therefore, less food is eaten causing a calorie deficiency. Rarely are homemade diets balanced for microminerals or vitamins. Owner neglect is also a frequent contributing factor in malnutrition.³¹

Recalls

Main article: 2007 pet food recalls

The 2007 pet food recalls involved the massive recall of many brands of cat and dog foods beginning in March 2007. The recalls came in response to reports of renal failure in pets consuming mostly wet pet foods made with wheat gluten from a single Chinese company, beginning in February 2007. After more than three weeks of complaints from consumers, the recall began voluntarily with the Canadian company Menu Foods on March 16, 2007, when a company test showed sickness and death in some of the test animals. Soon after, there were numerous media reports of animal deaths as a result of kidney failure, and several other companies who received the contaminated wheat gluten also voluntarily recalled dozens of pet food brands.

By the end of March, veterinary organizations reported more than 100 pet deaths amongst nearly 500 cases of kidney failure, with one online database self-reporting as many as 3,600 deaths as of April 11. As of April 8, Menu Foods has confirmed only about 16 deaths. The U.S. Food and Drug Administration refuses to estimate the amount of sick or dead because there is no centralized government records database of animal sickness or death in the United States as there are with humans (such as the Centers for Disease Control). As a result, many sources speculate that the actual number of affected pets may never be known and experts are concerned that the actual death toll could potentially reach into the thousands.

Overall, several major companies have recalled more than 100 brands of pet foods, with most of the recalled product coming from Menu Foods. Although there are several theories of the source of the agent causing sickness in affected animals, with extensive government and private testing and forensic research, to date, no definitive cause has been isolated. As of April 10, the most likely cause, according to the FDA, though not yet proven, is indicated by the presence of melamine in wheat gluten in the affected foods. The Chinese company behind the contaminated wheat gluten has initially denied any involvement in the contamination, but is cooperating with Chinese and American investigators.

In the United States, there has been extensive media coverage of the recall. There has been widespread public outrage and calls for government regulation of pet foods, which had previously been self-regulated by pet food manufacturers. The United States Senate held an oversight hearing on the matter by April 12. The economic impact on the pet food market has been extensive, with Menu Foods losing roughly $30 Million alone from the recall. The events have caused distrust of most processed pet foods in some consumers.

Environmental impact

Further information: Overfishing

See also: Environmental effects of meat production

In a study on the impacts of the pet food industry on world fish and seafood supplies, researchers estimate that 2.48 million metric tonnes of fish are used by the cat food industry each year.³²³³ It was suggested that there needs to be "a more objective and pragmatic approach to the use of a limited and decreasing biological resource, for human benefit." Marine conservation activist Paul Watson argues that the reduction in forage fish such as those commonly used in cat food (sardines, herring, anchovy etc.) negatively affects fish higher up the food chain like cod, tuna and swordfish, not to mention marine mammals and birds.³⁴

See also

• Cat food brands

References

External links

Wikimedia Commons has media related to: Cat food

• From the U.S. Food and Drug Administration - Center For Veterinary Medicine
  • Pet Foods
  • Information For Consumers - FDA's Regulation Of Pet Food
  • Information For Consumers - Information On Marketing A Pet Food Product
  • Information For Consumers - Interpreting Pet Food Labels
  • Information For Consumers - Interpreting Pet Food Labels - Special Use Foods
  • Vegetarian Diets For Pets?
• The Vegetarian Society UK on concerns relating to a vegetarian diet for cats
• The Cat That Ate Tofu Alternet article on vegan cat food
• Vegan Pet Food: A Discussion Animal Voices audio interview with Evolution pet food CEO
• From Max's House Feline Medical And Behavior Database
  • Feline Nutrition
  • Cat Food Nutrient Profiles
  • Dry food v/s canned (wet) food
  • Dispelling The Myth That Pets Are Used In Pet Foods
• Dry foods and risk of disease in cats An article in The Canadian Veterinary Journal which disputes the claim that dry food is harmful
• Get The Facts - What's Really In Pet Food from Animal Protection Institute