Linoleic acid is an example of an Omega-6 fatty acid that also helps with the health of the cat’s skin by maintaining the integrity of their epithelial issues.
Linoleic acid is commonly found in plant-based oils, an ingredient that is commonly used as a source of Linoleic acid is sunflower oil.
Arach idonic acid is also essential to cats because they are unable to create it from linoleic acid due to an absence of the Delta 6 desaturase enzyme.
It’s important for their skin for the same reason as Linoleic acid and can be found in ingredients such as animal fat.
==== Vitamin A ====Vitamin A is a crucial nutritional component in the maintenance of feline skin and coat health.
In addition to its many other functions, vitamin A plays an important role in the keratinization of the skin, hair and nails along with assisting in the development of various epithelial tissues throughout the body.
The cells making up the epithelial tissues of the skin, respiratory and gastrointestinal tracts rely on vitamin A to successfully complete the process of mitosis in order preserve these tissues and repair any damages.
The mucous secreting cells of the respiratory and gastrointestinal epithelium also specifically require vitamin A to successfully produce a specialized protein referred to as muco proteins which aid in maintaining the health of these tissues.
Unlike most other mammals, the cat is unique in that they are unable to transform B-carotene to vitamin A and therefore explicitly require activeforms of vitamin A which are only found in animal products.
This difference in metabolism is due to very low levels of activity of the enzyme B-carotene 15, 15’ dioxygenase infeline species.
The nutrient profiles developed by AAFCO currently advise a minimum of 3332IU/kg of vitamin A on a dry matter basis included in adult diets and 6668 IU/kg in the diets of growing kittens as well as pregnant or lactating female cats.
Common ingredients which help to incorporate the proper levels of vitamin A into feline diets include various types of liver as well as fish oils.
==== Vitamin E ====Vitamin E is an essential nutrient which needs to be included in the feline diet in order to protect the lipid components within cellular membranes of various tissues in the body.
Vitamin E is able to accomplish this through working with selenium and acting as an antioxidant to prevent free radicals from interacting with these fatty acid membrane components,resulting in reduced levels of oxidative stress.
This is particularly important in the skin as various oxidative environmental components can have very damaging effects if not protected by vitamin E.
The nutrient profiles developed by AAFCO currently advise a minimum dry matter inclusion of 40 IU/kg of vitamin E in the diet of cats throughout all stages of development.
Lipid metabolism is also a major contributor of free radicals, leading to an increased dietary requirement of vitamin E as the levels of polyunsaturated fatty acids in the diet increase.
Ingredients such as wheat germ as well as certain plant oils contain high levels of active vitamin E and are commonly added to feline diets which are carefully stored in order to prevent oxidative destruction of vitamin E prior to consumption.
==== B vitamins ==== ===== Biotin ===== Biotin can be provided in feline diets through the addition of cooked eggs, liver, milk, legumes or nuts.
Microorganisms living in the gastrointestinal tracts of cats are also able to synthesize and supply an alternative source of biotin if proper nutritional requirements are met.
Its main function in metabolism isto operate as a coenzyme for essential carboxylation reactions throughout the body1 however it has also been shown to aid in the management of certain skin diseases in cats.
Biotin is recommended by AAFCO to be included in feline diets at a minimum level of 0.
07 mg/kg ona dry matter basis throughout all stages of development.
==== Vitamin C ====Unlike humans, felines are able to utilize simple sugars glucose and galactose in a specializedpath way which occurs in the liver, referred to as the glucuronate pathway.
This path wayultimately produces the active form of vitamin C and maintains it at an adequate level, therefore it does not need to be separately included in their diet.
==== Low protein therapeutic diets and relation to the kidneys ==== Therapeutic diets with low protein have been adopted by a number of big pet food manufacturers with the goal of supporting renal health for cats with chronic kidney disease (CKD).
Chronic kidney disease or CKD is a highly prevalent condition in the feline population and is most common in the aging and older domesticated feline.
It has been shown that the lifespan of cats experiencing CKD can be extended by as much as 2 years when receiving therapeutic diets rather than regular maintenance diets.
The normal functions of the kidneys are to control a normal fluid balance and to excrete waste products from the blood into the urine.
One of the biggest concerns associated to CKD is to reduce the amount of stress put on the kidneys to process and excrete nitrogenous wastes from the body.
Low protein diets are a good choice for cats experiencing CKD as it lowers the amount of nitrogenous waste in the body helping to decease the strain put on the kidneys.
Nitrogenous wastes are produced by the body when amino acids obtained from the digestion of protein are metabolized to make energy.
The exact level of protein that is needed for therapeutic CKD diets is unclear, as sufficient protein in needed form aintenance while still offering a lower nitrogen level for the kidneys.
Low protein diets can be formulated as a wet or dry food, with the main difference being the moisture content.
These diets are formulated specifically to support the kidneys and urinary tract andalso to help prevent the progression of CKD.
There are certain dietary parameters that these diets follow on top of low protein such as low phosphorus, high energy density, a higher fat content and inclusion of omega-3 fatty acids to aid the kidneys in different ways.
Formulating the diet to have low phosphorus is very important as restricting the amountin the diet has been proven to decrease the progression of CKD.
The reason that plasmaphosphorus concentration should be kept low for low protein therapeutic diets is because phosphorus can be deposited into soft tissues and become mineralized which can cause kidney damage.
Formulating these diets with higher amounts of fat is important to make sure thefood is palatable in the absence of protein and promote an increased caloric intake.
The higher fat content will also spare the use of protein for energy and help decrease stresson kidney.
This inclusion of higher fat content also increase the energy density of the food which is important for cats with decreased appetites.
Omega-3 fatty acids are included in therapeutic diets because of their anti-inflammatory properties to aid the diseased kidneys.
==== Low protein diets and relation to the liver ==== Low protein diets should not be fed to cats with the liver condition known as hepatic encephalopathy because severe protein restriction can be detrimental to animals with this condition.
Cats with this condition should be fed a diet with high quality protein sources that have adequate amounts of the amino acids taurine and arginine.
=== High energy diets ===A high energy diet is generally high in fat.
Compared to carbohydrates and protein, fat provides much more energy, at 8.
High energy diets generally have a fat content greater than 20% on a dry matter basis.
A high energy diet is appropriate for cats who are undergoing growth, recovering from illness, are pregnant or lactating, as their energyrequirements are higher than otherwise.
A lactating or gestating cat requires a nutrient-denseand highly digestible diet to withstand the high levels of stress being placed on her body.
These conditions are found in cat food that is formulated for growth, performance,or high energy during all life stages.
To maintain a neutral energy balance and thus maintain body weight, energy intake should increase with energy expenditure.
Studies that relate the number of meals offered to cats per day to their daily activity levels have shown conflicting results.
It has been shown that cats offered four meals a day or a random number of meals a day have similar energy levels, greater than those fed only one mealper day.
It has been postulated that this increased energy level could be due to purported spikes in activity before being fed, known as food anticipatory activity.
Other studies on female cats have found that increasing the daily amount of food may actually decrease their daily activity levels.
The age, sex, and whether cats are intact or have been spayed/neuteredare all factors controlling activity level.
As cats age, there is evidence that their metabolic energy requirements may increase, especially after 12 or 13 years old, but other evidence suggests that metabolic energy needs are not dissimilar at different ages.
Furthermore,it has been shown that cats over 12 years old are more likely to be underweight than younger cats, so a high calorie diet may be appropriate to treat weight loss, and thus to maintain an appropriate body condition score.
Weight loss can occur when the cat expends more energy but does not increase its food energy intake.
It has also been demonstratedthat as cats age, they are less able to digest and thus absorb dietary fats and proteins.
Pregnancy and lactation are strenuous periods on the female cat.
During pregnancy a cat shouldgain 38% of their body weight by the time they are ready to give birth.
It is recommended that a cat’s diet should contain 4000 kcal ME per day while pregnant; during lactation it is recommended that the cat consumes 240 – 354 kcal/ME / kg of body weight.
Studies show that increasing the intake of food for a pregnant animal in order to help it gain weight can have negative effects.
It is acknowledged that rather than increasing intake, feeding a highly energy dense food is a way to ensure that the female cat, or queen, receives adequate energy and nutrient requirements are met.
It has been found that nutritional support consistent with the resting energy requirement (RER) soon after surgery or the onset of illness decreases the mortality rate and the duration of hospitalization in cats.
A recovering cat needs enough energy (calories), as well as more protein and fats.
Critical care diets are formulated to be highly palatable and digestible, as well as high energy density.
This limits the mass of food required to be consumed to meet the RER.
This type of high energy diet has proven to be very important in the nutritional support of post-operativeand ill cats.
=== Vegan and vegetarian diets ===Vegetarian or vegan cat food has been available for many years, and is targeted primarilyat vegan and vegetarian pet owners.
While a small percentage of owners choose such adiet based on its perceived health benefits, the majority do so due to ethical concerns.
Despite this, most vegans who feed their cats a vegan diet believe that a vegetarian dietis healthier than a conventional diet.
There is much controversy over feeding cats a vegetarian diet.
While there is anecdotal evidence that cats do well on vegetarian food, studies on commercial and homemade vegetarian cat foods have found nutritional inadequacies.
As obligate carnivores, cats require nutrients (including arginine, taurine, arachidonic acid, vitamin A, vitamin B12 and niacin) found in meat sources.
Plant sources do not contain enough of these.
Vegetarian pet food companies try to correct these deficiencies by adding synthetically produced nutrients.
According to the United States National Research Council, “Cats require specific nutrients, not specific feed stuffs.
“Cats on a vegan diet can develop abnormally alkaline(high pH) urine as plant-based proteins are more alkaline than the meat-based foods which cats have evolved to eat.
When the urine becomes too alkaline, there is an increased risk offormation of struvite (also known as magnesium ammonium phosphate) bladder crystals and/orstones.
Calcium oxalate stones can also occur if the urine is too acidic.
Such stones can create irritation and infection of the urinary tract and require veterinary treatment.
Organizations that advocate vegan or vegetarian diets for people have split opinions regarding vegetarian or vegan cat food.
The International Vegetarian Union, the Vegan Society and PETA are some of the organizations that support a vegan or vegetarian diet for cats.
But 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 would need to be supplemented, and recommend that those who want to try should consult a veterinarian or animal nutritionist.
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.
The animal welfare organization American Society for the Prevention of Cruelty to Animals, although suggesting a supplemented vegetarian diet for dogs, recommends against vegetarian and vegan diets for cats.
The Association of Veterinarians for Animal Rights (now Humane Society Veterinary Medical ) accepts that a plant-based diet can be nutritionally adequate, but stated in August 2006 that such diets “cannot at this time be reliably assured”.
This position was based on a 2004 study demonstrating that of both of the two commercially available vegetarian cat diets tested against the AAFCO standard were nutritionally deficient.
The formulation error in one of these diets was promptly identified and corrected.
Nevertheless,it remains likely that formulation errors will result in nutritional deficiencies ina wide range of commercially available diets from time to time, whether meat-based, vegetarian or vegan.
Hence, regular (at least, annual) veterinary checkups of all companion animalsis recommended, and brands may be occasionally varied.
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 exists.
One vegan cat food manufacturer has stated that “because of the relative acidity of meat to vegetable protein, some vegan cats suffer from [Urinary tract problems].
” A quarter of cat owners who feed their cats a vegetarian diet perceive feline lower urinary tract disease as a health risk of such a diet.
In 2006, the first study of the health of a population of long-term vegetarian cats was published in the Journal of the American Veterinary Medical Association.
Most of the cats were fed a commercially available vegan diet, though 35% were allowed outdoors.
The study consisted of telephone questionnaires of the caregivers of 32 cats, and analysis of blood samples from some of the cats.
The blood samples were tested for taurine and cobalamin deficiencies.
Cobalamin levels were normal in all cats.
Taurine levels were low in 3 out of 17 cats tested, but not low enough to be considered clinically deficient.
97% of the caregivers perceived their cats to be healthy, including those with low taurine levels.
Formulation of a nutritionally adequate vegan cat diet has its limitations.
Recurring errors during formulation include insufficient protein content, insufficient calcium and phosphorus, along with an unbalanced calcium to phosphorus ratio which strays from the ideal range of 0.