Human skin

Overall Requirements for Baccalaureate Degrees

Human nutrition
Which of the following most accurately depicts the difference between acute and chronic pain? Adipose tissue is mostly fat about 87 percent , but it also contains some protein and water. The dietary concentrations listed in the NRC tables are based on a given amount of feed intake; if intake is less than the amount listed, the dietary concentration may need to be increased to ensure an adequate daily intake of the nutrients. A lack of sufficient taurine in a cat's diet can cause blindness and a type of heart disease called dilated cardiomyopathy. If your cat still hates it, you can either decant the oil into a gelcap, try finding a less smelly product, or discuss with your vet whether to continue with the supplement. When based on digestible phosphorus, the ideal ratio of calcium to digestible phosphorus is between 2:

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Dietary recommendations / Nutritional requirements

Dietary fibre is thought to provide important protection against some gastrointestinal diseases and to reduce the risk of other chronic diseases as well.

Lipids also contain carbon, hydrogen, and oxygen but in a different configuration, having considerably fewer oxygen atoms than are found in carbohydrates. Lipids are soluble in organic solvents such as acetone or ether and insoluble in water, a property that is readily seen when an oil-and-vinegar salad dressing separates quickly upon standing.

The lipids of nutritional importance are triglycerides fats and oils , phospholipids e. Lipids in the diet transport the four fat-soluble vitamins vitamins A, D, E, and K and assist in their absorption in the small intestine. They also carry with them substances that impart sensory appeal and palatability to food and provide satiety value, the feeling of being full and satisfied after eating a meal.

Fats in the diet are a more concentrated form of energy than carbohydrates and have an energy yield of 9 kilocalories per gram. Adipose fatty tissue in the fat depots of the body serves as an energy reserve as well as helping to insulate the body and cushion the internal organs.

The major lipids in food and stored in the body as fat are the triglycerides, which consist of three fatty acids attached to a backbone of glycerol an alcohol. They are classified as saturated or unsaturated according to their chemical structure. A point of unsaturation indicates a double bond between two carbon atoms, rather than the full complement of hydrogen atoms that is present in saturated fatty acids. A monounsaturated fatty acid has one point of unsaturation, while a polyunsaturated fatty acid has two or more.

The common fatty acids in foods are listed in the table. Fatty acids found in the human diet and in body tissues range from a chain length of 4 carbons to 22 or more, each chain having an even number of carbon atoms. Of particular importance for humans are the carbon polyunsaturated fatty acids alpha-linolenic acid an omega-3 fatty acid and linoleic acid an omega-6 fatty acid ; these are known as essential fatty acids because they are required in small amounts in the diet.

The omega designations also referred to as n-3 and n-6 indicate the location of the first double bond from the methyl end of the fatty acid. Other fatty acids can be synthesized in the body and are therefore not essential in the diet.

About a tablespoon daily of an ordinary vegetable oil such as safflower or corn oil or a varied diet that includes grains, nuts , seeds , and vegetables can fulfill the essential fatty acid requirement.

Essential fatty acids are needed for the formation of cell membranes and the synthesis of hormone -like compounds called eicosanoids e. The consumption of fish once or twice a week provides an additional source of omega-3 fatty acids that appears to be healthful. A fat consisting largely of saturated fatty acids, especially long-chain fatty acids, tends to be solid at room temperature; if unsaturated fatty acids predominate, the fat is liquid at room temperature.

Fats and oils usually contain mixtures of fatty acids, although the type of fatty acid in greatest concentration typically gives the food its characteristics. Butter and other animal fats are primarily saturated; olive and canola oils, monounsaturated; and fish, corn , safflower , soybean, and sunflower oils, polyunsaturated. Although plant oils tend to be largely unsaturated, there are notable exceptions, such as coconut fat , which is highly saturated but nevertheless semiliquid at room temperature because its fatty acids are of medium chain length 8 to 14 carbons long.

Saturated fats tend to be more stable than unsaturated ones. The food industry takes advantage of this property during hydrogenation , in which hydrogen molecules are added to a point of unsaturation, thereby making the fatty acid more stable and resistant to rancidity oxidation as well as more solid and spreadable as in margarine.

However, a result of the hydrogenation process is a change in the shape of some unsaturated fatty acids from a configuration known as cis to that known as trans. Trans -fatty acids, which behave more like saturated fatty acids, may also have undesirable health consequences. A phospholipid is similar to a triglyceride except that it contains a phosphate group and a nitrogen -containing compound such as choline instead of one of the fatty acids.

In food, phospholipids are natural emulsifiers , allowing fat and water to mix, and they are used as food additives for this purpose. In the body, phospholipids allow fats to be suspended in fluids such as blood , and they enable lipids to move across cell membranes from one watery compartment to another. The phospholipid lecithin is plentiful in foods such as egg yolks, liver, wheat germ, and peanuts. However, the liver is able to synthesize all the lecithin the body needs if sufficient choline is present in the diet.

Sterols are unique among lipids in that they have a multiple-ring structure. The well-known sterol cholesterol is found only in foods of animal origin—meat, egg yolk , fish , poultry , and dairy products. There are a number of sterols in shellfish but not as much cholesterol as was once thought. Cholesterol is essential to the structure of cell membranes and is also used to make other important sterols in the body, among them the sex hormones, adrenal hormones , bile acids, and vitamin D.

However, cholesterol can be synthesized in the liver , so there is no need to consume it in the diet. Cholesterol-containing deposits may build up in the walls of arteries, leading to a condition known as atherosclerosis , which contributes to myocardial infarction heart attack and stroke. Furthermore, because elevated levels of blood cholesterol, especially the form known as low-density lipoprotein LDL cholesterol, have been associated with an increased risk of cardiovascular disease , a limited intake of saturated fat—particularly medium-chain saturated fatty acids, which act to raise LDL cholesterol levels—is advised.

Trans-fatty acids also raise LDL cholesterol, while monounsaturated and polyunsaturated cis fats tend to lower LDL cholesterol levels. The complex relationships between various dietary lipids and blood cholesterol levels, as well as the possible health consequences of different dietary lipid patterns, are discussed in the article nutritional disease. Proteins , like carbohydrates and fats, contain carbon, hydrogen, and oxygen, but they also contain nitrogen , a component of the amino chemical group NH 2 , and in some cases sulfur.

Proteins serve as the basic structural material of the body as well as being biochemical catalysts and regulators of genes. Aside from water, protein constitutes the major part of muscles, bones, internal organs, and the skin , nails , and hair.

Protein is also an important part of cell membranes and blood e. Enzymes , which catalyze chemical reactions in the body, are also protein, as are antibodies , collagen in connective tissue, and many hormones, such as insulin. Tissue proteins are in a dynamic equilibrium with proteins in the blood, with input from proteins in the diet and losses through urine , feces , and skin. In a healthy adult, adjustments are made so that the amount of protein lost is in balance with the amount of protein ingested.

However, during periods of rapid growth, pregnancy and lactation , or recuperation after illness or depletion, the body is in positive nitrogen balance, as more protein is being retained than excreted. The opposite is true during illness or wasting, when there is negative nitrogen balance as more tissue is being broken down than synthesized. Each gene makes one or more proteins, each with a unique sequence of amino acids and precise three-dimensional configuration.

Amino acids are also required for the synthesis of other important nonprotein compounds, such as peptide hormones, some neurotransmitters , and creatine. Food contains approximately 20 common amino acids, 9 of which are considered essential, or indispensable, for humans; i.

The essential amino acids for humans are histidine , isoleucine , leucine , lysine , methionine , phenylalanine , threonine , tryptophan , and valine. Conditionally indispensable amino acids include arginine , cysteine , and tyrosine , which may need to be provided under special circumstances, such as in premature infants or in people with liver disease, because of impaired conversion from precursors.

The relative proportions of different amino acids vary from food to food see table. Foods of animal origin— meat , fish , eggs , and dairy products —are sources of good quality, or complete, protein; i.

Gelatin , which lacks the amino acid tryptophan , is an exception. Individual foods of plant origin, with the exception of soybeans , are lower quality, or incomplete, protein sources. Lysine , methionine , and tryptophan are the primary limiting amino acids; i.

However, a varied vegetarian diet can readily fulfill human protein requirements if the protein-containing foods are balanced such that their essential amino acids complement each other. For example, legumes such as beans are high in lysine and low in methionine, while grains have complementary strengths and weaknesses.

Thus, if beans and rice are eaten over the course of a day, their joint amino acid patterns will supplement each other and provide a higher quality protein than would either food alone. Traditional food patterns in native cultures have made good use of protein complementarity. However, careful balancing of plant proteins is necessary only for those whose protein intake is marginal or inadequate. In affluent populations, where protein intake is greatly in excess of needs, obtaining sufficient good quality protein is usually only a concern for young children who are not provided with animal proteins.

The World Health Organization recommends a daily intake of 0. Thus, a kg pound man would need This recommendation, based on nitrogen balance studies, assumes an adequate energy intake.

Infants, children, and pregnant and lactating women have additional protein needs to support synthesis of new tissue or milk production. Protein requirements of endurance athletes and bodybuilders may be slightly higher than those of sedentary individuals, but this has no practical significance because athletes typically consume much more protein than they need. During conditions of fasting , starvation , or insufficient dietary intake of protein, lean tissue is broken down to supply amino acids for vital body functions.

Persistent protein inadequacy results in suboptimal metabolic function with increased risk of infection and disease. Vitamins are organic compounds found in very small amounts in food and required for normal functioning—indeed, for survival. Humans are able to synthesize certain vitamins to some extent. For example, vitamin D is produced when the skin is exposed to sunlight ; niacin can be synthesized from the amino acid tryptophan; and vitamin K and biotin are synthesized by bacteria living in the gut.

However, in general, humans depend on their diet to supply vitamins. When a vitamin is in short supply or is not able to be utilized properly, a specific deficiency syndrome results.

When the deficient vitamin is resupplied before irreversible damage occurs, the signs and symptoms are reversed. The amounts of vitamins in foods and the amounts required on a daily basis are measured in milligrams and micrograms.

Unlike the macronutrients, vitamins do not serve as an energy source for the body or provide raw materials for tissue building. Rather, they assist in energy-yielding reactions and facilitate metabolic and physiologic processes throughout the body. Vitamin A , for example, is required for embryonic development, growth, reproduction, proper immune function, and the integrity of epithelial cells, in addition to its role in vision.

The B vitamins function as coenzymes that assist in energy metabolism; folic acid folate , one of the B vitamins, helps protect against birth defects in the early stages of pregnancy. Vitamin C plays a role in building connective tissue as well as being an antioxidant that helps protect against damage by reactive molecules free radicals. Now considered to be a hormone , vitamin D is involved in calcium and phosphorus homeostasis and bone metabolism.

Vitamin E , another antioxidant, protects against free radical damage in lipid systems, and vitamin K plays a key role in blood clotting. Although vitamins are often discussed individually, many of their functions are interrelated, and a deficiency of one can influence the function of another. Vitamin nomenclature is somewhat complex, with chemical names gradually replacing the original letter designations created in the era of vitamin discovery during the first half of the 20th century.

Nomenclature is further complicated by the recognition that vitamins are parts of families with, in some cases, multiple active forms. Some vitamins are found in foods in precursor forms that must be activated in the body before they can properly fulfill their function. The 13 vitamins known to be required by human beings are categorized into two groups according to their solubility. The four fat-soluble vitamins soluble in nonpolar solvents are vitamins A, D, E, and K. Although now known to behave as a hormone, the activated form of vitamin D, vitamin D hormone calcitriol , is still grouped with the vitamins as well.

The nine water-soluble vitamins soluble in polar solvents are vitamin C and the eight B-complex vitamins: Choline is a vitamin-like dietary component that is clearly required for normal metabolism but that can be synthesized by the body.

Although choline may be necessary in the diet of premature infants and possibly of those with certain medical conditions, it has not been established as essential in the human diet throughout life. Different vitamins are more or less susceptible to destruction by environmental conditions and chemical agents. For example, thiamin is especially vulnerable to prolonged heating, riboflavin to ultraviolet or fluorescent light, and vitamin C to oxidation as when a piece of fruit is cut open and the vitamin is exposed to air.

In general, water-soluble vitamins are more easily destroyed during cooking than are fat-soluble vitamins. The solubility of a vitamin influences the way it is absorbed, transported, stored, and excreted by the body as well as where it is found in foods. With the exception of vitamin B 12 , which is supplied by only foods of animal origin, the water-soluble vitamins are synthesized by plants and found in both plant and animal foods.

Strict vegetarians vegans , who eat no foods of animal origin, are therefore at risk of vitamin B 12 deficiency. All vitamins are subject to degradation over time, and this process is accelerated by moisture, oxygen, trace minerals, heat, and light. Stabilized vitamin preparations and generous margins of safety are often applied to account for these losses. This is especially true if diets are pelleted, extruded, or stored for long periods.

Much of the phosphorus in feedstuffs of plant origin is complexed by phytate and is not absorbed efficiently by poultry. Consequently, it is critical that only the available phosphorus and not the total phosphorus levels be considered. Appropriate calcium nutrition depends on both the level of calcium and its ratio to that of available phosphorus. For growing poultry, this ratio should not deviate substantially from 2: The calcium requirement of laying hens is very high and increases with the rate of egg production and age of the hen.

The chick has requirements for 38 nutrients, together with an adequate level of metabolizable energy and water. Some additional nutrients may be necessary for growth and development under certain conditions. These include vitamin C, pyrroloquinoline quinone, and several heavy metals.

Non-nutrient antioxidants, such as ethoxyquin, are usually added to poultry diets to protect vitamins and unsaturated fatty acids from oxidation. Enzymes that increase the bioavailability of dietary phosphorus, energy, and protein are often used in poultry diets when their costs are not prohibitive. In some cases, phytase enzymes are used to decrease the amount of phosphorus in the excreta to meet environmental regulations.

Which of the following diseases is ubiquitous in almost every chicken flock throughout the world? Cardiology is not a required rotation at OVC, but I picked it up nonetheless because it is one of my weakest subjects. Nutritional Requirements of Poultry. Energy Requirements and Feed Intake: Other Nutrients and Additives: Poultry Nutritional Requirements of Poultry. Nutrient Requirements of Growing Pullets a Age wk. Nutrient Requirements of Broilers a Age b.

Protein and Amino Acid Requirements of Turkeys a. Nutrient Requirements of Pheasants a Energy base. Body weight g b. Starting 0—2 wk 2, Growing 2—7 wk 3, Persuading Your Cat to Eat. Tips on Giving Subcutaneous Fluids. How to Give Subcutaneous Fluids with a Syringe. Coping with Your Loss. Diese Webseite auf Deutsch. Tanya, Thomas and Ollie. My Multi Ailment Cat, Harpsie. Find Me on Facebook.

Follow Me on Twitter. This page starts with a brief overview of the physiological needs of cats generally. It then examines the nutritional requirements of CKD cats in particular, and includes a discussion of the reduced protein debate. It also discusses other nutritional issues, such as the importance of weight and muscle maintenance.

If you're feeling overwhelmed and just want some ideas on what to feed your cat, skip this page for now and read the Which Foods to Feed and P ersuading Your Cat To Eat pages instead. Physiological Needs of Cats. Cats are not small dogs.

They have unique physiological needs. When you are dealing with CKD, you need to meet these basic needs but also cater as far as possible for their CKD-related needs.

There are many different opinions about the best food for cats, and the debate can get quite heated. I don't wish to focus on that here, but rather to explain the basic needs of cats from a scientific perspective.

Cats are obligate carnivores. This does not mean they can only eat meat. It means that, unlike other species, such as humans and dogs, they cannot manufacture certain amino acids essential to life themselves. In order to obtain these amino acids, they must eat food which contains them, and ideally that means they must eat meat, though they may also be able to obtain them from other sources for example, corn gluten meal, the protein part of corn, actually contains all the amino acids which cats need.

It is a myth that our domestic cats are miniature versions of the big cats such as lions. Big cats are part of a pride, and hunt together. Domestic cats, in contrast, are solitary predators, and if they are living in their own version of the wild, they only eat what they can catch. They catch mice, insects, whatever passes by or what they can hunt. This means they have evolved to eat little and often. They eat very little plant material or carbohydrate, only what would be found in a mouse's stomach, though they may sometimes also eat small amounts of grass.

Originally cats were desert animals, so they evolved to not want to drink much. Therefore ideally cats also need to eat foods containing a reasonable amount of water. So to summarise, healthy cats need foods containing a large percentage of meat-based protein, with limited vegetables and grains. It becomes a little more complicated when you add CKD to the mix. You still want to feed a diet that meets your cat's basic physiological needs, as outlined above, but if possible you also want to feed a diet that can help with the CKD.

There are two main concerns with diet in CKD cats:. It is essential to keep your cat eating, and to maintain weight and muscle as much as possible.

Below I discuss the importance of weight management and calorie intake in CKD cats, followed by an explanation of the main components of the feline diet, such as protein and phosphorus, and how they impact on CKD. The protein section includes information about the pros and cons of a reduced protein diet.

I recommend that ideally you read this page so you can understand the main components of feline diets. Then you can read the Which Foods to Feed page, which discusses food choices including therapeutic kidney diets, and what to do if your cat refuses to eat them. Remember, the most important thing is that your cat eats. I cannot emphasise this enough. If you're struggling to get any food at all into your cat, check the P ersuading Your Cat To Eat page.

Maintaining weight and muscle is extremely important. Anorexic cats cats who have stopped eating and cachexic cats cats who have lost a lot of muscle have a worse prognosis than cats of a normal weight, so it is essential to monitor your cat's weight and body condition closely, and above all to keep your cat eating. The World Small Animal Veterinary Association has a body condition diagram showing how to gauge your cat's physical condition, as does Purina.

If you are lucky enough to have an slightly overweight CKD cat, rejoice, and personally I would not put him or her on a diet, because as the CKD progresses, your cat will almost certainly lose weight anyway.

Older cats over the age of ten are prone to weight loss, even if they have no underlying health problems. It is not known exactly why older cats lose weight, but it is thought it may be at least in part because their bodies become less able to digest nutrients, particularly fat and protein. Low protein digestibility also seems to affect mature and geriatric cats. The incidence of low fat and protein digestibility tends to occur in the same cats. A marked decline apparently becomes particularly prevalent after around age Whatever the precise reason, weight loss in older cats is not good news.

Emaciated cats had a significantly higher risk of death compared with cats in optimal body condition. Perez-Camargo et al demonstrated that body weight, lean body mass, and fat mass decline in cats over the age of 12 years, particularly in the last 1 to 2 years of life. Even in younger cats, low body weight can be a concern. Mechanisms causing loss of lean body mass in kidney disease Mitch WE The American Journal of Clinical Nutrition 67 pp explains more about this problem in humans.

It is therefore extremely important to monitor your cat's weight and to keep him or her eating. I recommend weighing your cat at least weekly. There are links on buying scales suitable for weighing cats here. Muscle wasting is also common in CKD cats.

This is partly because most CKD cats are elderly and the elderly are prone to sarcopaenia, which is the age-related loss of muscle. CKD cats may also suffer from cachexia.

Cachexia is defined as a metabolic syndrome in which inflammation is the key feature and so cachexia can be an underlying condition of sarcopenia. Recently, cachexia has been defined as 'a complex metabolic syndrome associated with underlying illness and characterized by loss of muscle mass with or without loss of fat mass. The prominent clinical feature of cachexia is weight loss in adults. CKD is one such underlying illness.

Although the prevalence of cachexia in dogs and cats with CKD has not specifically been measured, it appears to be relatively high and likely has negative clinical effects. Since creatinine , one of the measures of kidney function, is a by-product of muscle, cats who lose a lot of muscle may have reduced creatinine levels, because they cannot produce as much creatinine. The Merck Veterinary Manual states "Serum creatinine levels can be falsely lowered in patients with severe muscle wasting.

Over months cats can down regulate their protein needs and switch to use other pathways, but in the short and intermediate term, muscle will be catabolized. The resulting muscle wasting and decreased mass reduces the serum level of creatinine Cr measured.

You may therefore think your cat's CKD is improving because the creatinine is falling, when in fact this is not the case. Cats with hyperthyroidism also tend to lose a lot of muscle, which is an additional headache if your cat has both CKD and hyperthyroidism. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: It concluded "Omega-3 fatty acids stimulate muscle protein synthesis in older adults and may be useful for the prevention and treatment of sarcopenia.

When considering a food for their CKD cats, many people focus on its phosphorus and protein levels, but it is also important to consider the calorie content, especially if you want your cat to keep on or gain weight and muscle. A healthy cat needs approximately calories per day per pound of body weight, or possibly more if the cat is particularly active.

The National Research Council states that a lean adult cat weighing 5 lbs needs around calories a day, and a lean adult cat weighing 10 pounds needs around calories a day.

The World Small Animal Veterinary Association Global Nutrition Committee makes similar recommendations for the average healthy adult cat at a healthy weight. This level of intake is unlikely to be sufficient for older cats. In Feeding older cats - an update in new nutritional therapies Sparkes A Topics in Companion Animal Medicine 26 1 pp, Dr Sparkes states that older cats need more calories than younger cats, preferably in the form of protein. He adds that older cats also seem to do better when fed a diet containing prebiotics , antioxidants and essential fatty acids.

Many sources, including the National Research Council, also believe that chronically sick cats need more calories, possibly as many as twice the number of calories as healthy cats. So obviously, feeding a teaspoonful of food a day is not going to be enough to maintain your CKD cat's weight, let alone increase it if your cat is too thin. Another thing to consider is the water content of the food. Although increased fluid content can be helpful for CKD cats, who are at risk of dehydration, the downside is that such foods may make the cat feel relatively full while providing insufficient calories for the cat's needs.

This is often the case with simple foods that consist largely of meat or fish. Lower fat foods may also contain fewer calories. Therapeutic kidney diets are more calorie dense than standard maintenance diets. You can check the calorie content of some US foods here canned and here dry. I am working on adding the calorie content to the UK food data tables. Stanley Marks discusses feline dietary and calorie needs in Diagnostic and therapeutic approach to the anorectic cat , Presentation to the World Small Animal Veterinary Association World Congress The ins and outs of managing feline chronic kidney disease Codi M Today's Veterinary Technician has a formula Box 1 for calculating the daily energy requirement for neutered CKD cats.

PetSci has a calorie calculator. Some manufacturers provide data about the metabolisable energy ME of their foods. With a higher ME, your pet's body will receive more energy from a smaller amount of food. This can be helpful for CKD cats who tend not to have much appetite. Food Composition and Requirements. The usual guidelines for CKD cats are to feed a diet which has added potassium and essential fatty acids but which has reduced levels of protein, phosphorus and sodium.

It is helpful to understand the reasoning behind these recommendations. If you asked most people what was the main nutritional step to take for a cat with kidney disease, they would probably say "feed low protein.

This section discusses the role of protein in kidney disease and if and when to reduce the levels of protein which you feed. Protein is a molecular structure made up of a number of amino acids which are essential for the body to repair and maintain itself.

Cats have a higher need for protein than many other species because, unlike dogs or humans, they cannot manufacture certain of these amino acids e. These missing amino acids are only found in meat and corn gluten meal , and therefore cats must ideally eat meat in order to obtain these amino acids. This is why cats are known as obligate carnivores.

When people feed a cat a vegetarian diet which I definitely do not recommend for any cat , they provide these amino acids in the form of supplements, but cats are optimally designed to obtain them from meat.

The National Research Council NRC guidelines indicate a minimum daily protein requirement and a recommended daily protein allowance of 2. Let's crunch some numbers based on these recommendations:. These levels sounded low to me, and research indicates they probably are. The study states that " approximately 1.

This study provides evidence that nitrogen balance studies are inadequate for determining optimum protein requirements. Animals, including cats, can adapt to low protein intake and maintain nitrogen balance while depleting LBM. Loss of LBM and an associated reduction in protein turnover can result in compromised immune function and increased morbidity.

The minimum daily protein requirement for adult cats appears to be at least 5. Further research is needed to determine the effect, if any, of body condition, age and gender on protein requirements. On this basis, a 10lb 4. To complicate matters, older cats may have higher protein requirements. Pet Education has an overview of protein requirements in cats. Studies performed on humans and rats with CKD found that feeding reduced levels of protein appeared to be beneficial and might help prolong life.

Therefore researchers wondered if a lower protein intake might have a similar beneficial effect for cats. In many of the early studies in cats, the cats had a large percentage of their kidneys surgically removed in order to induce kidney failure; this is not the way kidney disease tends to develop in most cats, who usually have chronic kidney disease rather than acute kidney injury.

Even so, the results were not necessarily what might have been expected. Some of the cats fed the high protein diet did develop transient hypokalaemia low potassium levels , which might have been because the low protein diet contained more potassium. No real differences were seen after a year, and there was no change in GFR in any group. A vet from Ohio State University College of Veterinary Medicine stated with regard to this study "recent findings in cats with induced renal insufficiency suggest that feeding diets restricted in protein may not be necessary for this species.

In Effects of dietary p rotein intake on re nal f unction Supplement to Compendium on Continuing Education for the Practising Veterinarian 21 Dr Finco stated "the negative results from the second study indicate that protein restriction in cats with renal disease remains to be proven as an effective maneuver for ameliorating progression of renal disease". These studies seem to indicate that a reduced protein intake is not necessarily of any real benefit to CKD cats. However, there are also some studies into the use of therapeutic kidney diets , which have reduced protein levels rather than extremely low protein levels along with other attributes ; and more sensibly, research began to focus on cats with naturally occurring CKD.

In Survival of cats with naturally occurring chronic renal failure: Some of the cats presumably in both groups were also given phosphorus binders. The cats fed the therapeutic kidney diet survived longer than the other cats, but it is not clear whether this was due to the reduction in phosphorus intake rather than the reduction in protein intake. This is the first prospective dietary study involving naturally occurring feline CKD cases where survival from first diagnosis has been assessed.

The studies described above were focusing on whether a reduced protein intake might slow the progression of kidney disease and help the cat live longer. The other issue is whether feeding reduced protein might help the cat feel better. This study found that feeding a therapeutic kidney diet helped to keep BUN levels lower and appeared to help prevent metabolic acidosis in cats with more advanced CKD. Thus in this study the therapeutic kidney diet not only appeared to reduce the number of deaths, but the cats also exhibited fewer signs of illness.

This is because, during the breakdown of dietary protein in the digestive process, waste substances are created which are filtered out of the blood by the kidneys and excreted via urination. This is sometimes referred to as the removal of nitrogenous wastes.

Contrary to popular opinion, BUN and creatinine are not toxins themselves. However, BUN levels correlate with uraemic toxin levels, i. If you feed a reduced protein diet, this reduces the amount of nitrogenous wastes that must be processed by the kidneys.

This usually leads to a reduction in BUN levels and in turn the cat will often feel and act better. These clinical signs, that are often referred to as uremia, can be caused by an accumulation of the breakdown products of protein metabolism sometimes referred to as nitrogenous waste products.

This protein comes from both the protein in your animal's diet, as well as mobilization and degradation of their own body's protein stores.

Consumption of protein in amounts greater than what your animal needs to maintain normal bodily functions can exacerbate these clinical signs. Anemia enhances the weakness and reluctance to eat in animals with renal failure. Anemia can occur for several reasons with renal disease, but one factor that is believed to make it worse is excessive dietary protein.

Nitrogenous waste products are believed to contribute to anemia by reducing the life span of red blood cells. The waste products may also enhance blood loss by leading to the formation of gastrointestinal ulcers and a reduction in blood clotting ability. It must also be remembered that when vets recommend therapeutic kidney diets, they are not only recommending reduced protein levels. Therapeutic kidney diets have other attributes, for example reduced protein diets also tend to contain less phosphorus, and phosphorus control is extremely important in CKD cats.

These foods also contain additional levels of potassium and essential fatty acids see below. You can read more about the attributes of therapeutic kidney diets on the Which Foods to Feed page. Of course, nothing is ever simple when it comes to cats, so there are also potential downsides with reduced protein intake. One common problem with reduced protein for cats, as you might expect, is weight loss. One study using healthy cats, Determining protein requirements: In study one, percent weight loss increased in a linear manner with decreasing protein intake.

Feeding cats with different nutritional needs: As a result, there may or may not be weight loss, but there will be muscle wasting as well as a deterioration in the hair coat quality. Because protein is component in antibodies, immune function may be compromised; anemia may be exacerbated due to the lack of building blocks for hemoglobin; albumin levels may decrease and tissue healing will be affected. Protein is a preferred flavour, so if a cat is already inappetant, restricting protein may result in inadequate intake of all nutrients, and the protein intake may fall below that required for normal function.

Slowing the progression of chronic renal failure Grauer GF states "There are, however, potential undesirable effects associated with dietary protein reduction. Reduced protein diets are also of concern for cats with metabolic acidosis, because, according to Nutrition and renal function in cats and dogs: Sufficient, High Quality Protein.

As discussed previously, during the breakdown of dietary protein in the digestive process, waste substances are created which are filtered out of the blood by the kidneys and excrete d via urination. Unfortunately damaged kidneys find it harder to do this, which is why your CKD cat may feel poorly. You will note the reference to not feeding more protein than your cat's body needs to maintain normal function. This is the crux of the matter.

You do not want to feed an extremely low level of protein so your cat suffers weight loss and malnutrition; but nor do you want to be loading your cat's body with unnecessarily high levels of protein which contribute to your cat feeling ill.

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