User:Emma.thornton/sandbox

 Vegetarian/Vegan Cat Food 

[Cats are obligate carnivores: their physiology has evolved to efficiently process meat, and they have difficulty digesting plant matter. In contrast to omnivores such as rats, which only require about 4% protein in their diet, about 20% of a cat's diet must be protein. Cats are unusually dependent on a constant supply of the amino acid arginine, and a diet lacking arginine causes marked weight loss and can be rapidly fatal. Another unusual feature is that the cat cannot produce taurine, with taurine deficiency causing macular degeneration, wherein the cat's retina slowly degenerates, causing irreversible blindness.]

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Taurine (done), arachidonic acid (done), niacin (done), vitamin A (done), Vitamin D3 (done), Arginine (done)

This is due to the hepatic activity of cystinesulfinic acid decarboxylase being low in cats. This limits the ability for cats to biosynthesize the amino acid taurine from its precursor amino acids ethionine and cysteine, which ultimately results in inadequate taurine production needed for normal function. Deficiencies in taurine result in compensated function of feline cardiovascular and reproductive systems. These abnormalities can also be accompanied by developmental issues in the central nervous system along with degeneration of the retina.

In order to produce the essential vitamin niacin for use in the cat, tryptophan is needed for conversion purposes. However, due to a competing pathway with Acetyl CoA, niacin becomes deficient and supplementation is required. This process occurs when an overactive enzyme, Picolinic acid carboxylase, converts the vitamin B6 precursor, Picolinic acid, into the alternate compound Acetyl coenzyme A, instead of converting Quinolinate into Nictotinic acid mononlucleotide (niacin). Niacin is required in cats as it supports enzyme function. If niacin is deficient in the diet, anorexia, weight loss and an increase in body temperature can result.

Preformed Vitamin A is required in the cat for retinal and reproductive health. Vitamin A is considered to be a fat-soluble vitamin and is seen as essential in a cat's diet. Normally, the conversion of $\beta$-carotenes into vitamin A occurs in the intestine (more specifically the mucosal layer) of species, however cats lack the ability to undergo this process. Both the kidney and liver are contributors to the use of vitamin A in the body of the majority of species while the cats liver does not produce the enzyme beta carotene 15, 15' monooxygenase which converts the $$\beta$$-carotene into retinol (vitamin A). To summarize, cats do not have high levels of this enzyme leading to the cleavage and oxidation of carotenoids not taking place.

Vitamin D3 is a dietary requirement for cats as they lack the ability to synthesize vitamin D3 from sunlight. Cats obtain high levels of the enzyme 7-dehydrocholestrol delta 7 reductase which causes immediate conversion of vitamin D3 from sunlight to 7-dehydrocholesterol. This fat soluble vitamin is required in cats for bone formation through the promotion of calcium retention, along with nerve and muscle control through absorption of calcium and phosphorus.

Arginine is an essential additive in cat food because cats have low levels of the enzymes aminotransferase and pyrroline-5-carboxylate which are responsible for the synthesis of ornithine and citruline in the small intestine. Citruline would typically go on to the kidneys to make arginine, but because cats have a deficiency in the enzymes that make it, citruline is not produced in adequate quantities to make arginine. Arginine is essential in the urea cycle in order to convert the toxic component ammonia into urea that can then be excreted in the urine. Because of its essential role, deficiency in arginine results in a build up of toxic ammonia and leads to hyperammonemia. The symptoms of hyperammonemia include lethargy, vomiting, ataxia, hyperesthesia and can be serious enough to induce death and coma in a matter of days if a cat is being fed a arginine free diet. The quick onset of these symptoms is due to the fact that diets devoid in arginine will typically still contain all of the other amino acids, which will continue to be catabolized by the body producing mass amounts of ammonia that very quickly build up with no way of being excreted.

Cats, like all mammals, need to get the essential fatty acid, linoleic acid, from their diet. Most mammals can convert linoleic acid to arachidonic acid, as well as the omega 3 fatty acids(eicosapentaenoic acid and docosahexaenoic acid) through the activity of enzymes, but this process is very limited in cats. The Δ6-desaturase enzyme eventually converts linoleic acid, which is in its salt form linoleate, to arachidonate (salt form of arachidonic acid) in the liver, but this enzyme has very little activity in cats. This means that arachidonic acid is an essential fatty acid for cats as they lack the ability to create required amounts of linoleic acid. Deficiency of arachidonic acid in cats is related to problems in growth, can cause injury and inflammation to skin (e.g. around the mouth) decreased platelet aggregation, fatty liver, increase in birth defects of kittens whose queens were deficient during pregnancy, and reproductive failure in queens. Arachidonic acid can also be metabolized to eicosanoids that create inflammatory responses which are needed to stimulate proper growth and repair mechanisms in the cat.

The nutrient chart provides a list of the many nutrients cats require as well as the use of the nutrients in the body and the effects of the deficiency.

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For the Vegan diet page

Formulation of a nutritionally adequate vegan cat diet has its limitations. Reoccurring errors during formulation include insufficient protein content, insufficient calcium and phosphorus, along with an unbalanced calcium phosphorus ratio which strays from the ideal ratio of 0.9 to 1.1:1. This is in addition to commonly occurring deficiencies of taurine, arachidonic acid, sodium, vitamin A, vitamin B12 as well as trace minerals.

The reason for these dietary essential nutrients can be found in the physiology section of the Cat page.

Protein and fat content in a vegan cat diet can be balanced through the inclusion of tofu and yeast. Over the counter supplementation of vitamins and minerals in some cases may not meet nutrient requirements as they come in varying amounts. As vegan diets are mainly composed of plants sources, some vitamins and minerals may be deficient as plant sources do not provide adequate quantities. For instance, plant materials do not provide the preformed vitamin A which cats cannot synthesize, therefore supplementation is needed. As mentioned previously, arginine is a dietary requirement of cats, as it plays a critical role in bodily functions (refer to the physiology section in the Cat page). Some ingredients that may be seen in vegan cat diets that provide arginine, are pumpkin seed, almond, soya flour, lentil seeds and oat flakes (see table one). The addition of arachidonic acid to cat foods typically comes from animal based sources. In vegan cat diets, arachidonic acid can be added through the inclusion of algal biomass or seaweed. However, providing excessive amounts of seaweed to the diet can be detrimental, as seaweed is very high in selenium allowing for toxicity to be possible. A vitamin D3 source, Lanolin, a constituent of sheep's wool, is often used as a form of supplementation for this vitamin. However, due to its animal origin this would not be appropriate for supplemental use in a vegan cat diet so a synthetic form of vitamin D3 is required. Vegan vitamin D3 can be synthesized through the combination of the ingredients lichen, chicory extract and chamomile extract. Some vegan sources with high niacin content are Brewer's yeast, oats, wheat flours, sunflower seeds and sesame seeds. AAFCO requires cat food to have 60 mg of niacin per kg of cat food on a dry matter basis. Taurine can be biosynthesized or can be obtained in the diet by eating animal sources for food or algae. For cats, taurine is an essential amino acid acid as they cannot biosynthesize it from the amino acids methionine or cysteine, therefore, they must obtain it endogenously. A synthetic form of taurine must be supplemented in adequate amounts in a vegan cat diet (as plant sources do not have taurine) to ensure taurine deficiencies do not occur (refer to the physiology section on the Cat page). _________________________________________________________________________________________________________________________________________________________________

Vegan cat food chart

Arginine, arachidonic acid, biotin, taurine, vitamin B12

Taurine

- cardiovascular and reproductive problems

- developmental problems in the central nervous system

- retinal degeneration

Function: Choline Arachidonic acid
 * Vision
 * Digestion
 * Heart muscle function
 * Normal pregnancy
 * Fetal development
 * Immunity
 * Deficiency
 * Fatty liver in kittens
 * Lower motivation to eat in kittens
 * Decreased growth rate in kittens

- lack of inflammatory response

- improper blood clotting

- malfunction of reproductive and gastrointestinal systems

Vitamin B12

- lack of enzymatic processing

- gastrointestinal tract distress such as vomiting and diarrhea

- weight loss

- anorexia

Biotin

- Females: experience dried secretions from the nasal, salivary and lacrymal regions

- weight loss

- alopecia

- dermatitis around the mouth