What requirements does good dog food have to meet?
There are all sorts of claims made about feeding dogs, therefore it seems to us to be a good idea to indicate clearly the requirements that a COMPLETE DRY FOOD for dogs must meet.
(In this information there is discussion of nutrients and foodstuffs. For the avoidance of doubt: foodstuffs are the products from which the food is composed. Nutrients are the substances released during digestion of these products, and taken up in the dog’s body.)
- The dog must eat the food eagerly at all times.
- The food has to be in balance; this means that all the nutrients and other substances in the food must be in balance with each other and above all attuned to the total requirements of the dog, and this means;
- That the composition of the food must comply with the latest Nutrient Requirements of Dogs, from the Committee on Animal Nutrition. These are the most recent, scientifically established, and internationally recognised standards for dog foods.
- The food must be free of chemical antioxidants (Ethoxyquine, BHT and/or BHA) and preservatives, which are completely unnecessary if pure foodstuffs have been used. Above all the antioxidant Ethoxyquine is very damaging for dogs in the long term.
- The food must be free of soya and cereal waste products, because these contain amongst other things a lot of phytates.
- The food may not contain destruction material, sourced from animals that have died or been put to sleep (forbidden in the whole EU since 1998, but widely permitted outside).
- Per kilogram of dry material the food must contain as much easily digestible energy as possible.
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The dog must eat the food eagerly at all times, so that he/she continues to take in everything which is necessary for optimal function, also in the long term. The smell and the taste of the food determine for the dog whether or not sufficient is eaten and whether he or she continues to find it tasty in the longer term. This must be achieved without using aroma and flavouring substances, because in the long term these can give rise to resistance to food. This is because the dog does not smell and taste the food in its totality, but each raw material separately.
Furthermore it is known from human medical sciences that for example children, in terms of character, can react very negatively to colouring, aroma, and flavourings. How this is for our dogs has till now not been sufficiently investigated. This is the reason that the food, also in respect of aroma and taste, must be of a quality that does not require aroma and flavouring substances. This is only achievable by the use of pure materials which, also in combination, guarantee a good aroma and taste.
It can occur that a dog which has always received food containing aroma and flavouring substances, may have difficulty when changing over to food that has a natural aroma and taste. If this is the case you are better off giving the dog a complete tripe raw meat diet for a couple of days before you switch over.
It regularly occurs that the dogs eat a lot of an optimal food in the beginning to make up for deficiencies present (mostly trace elements and certain amino acids). In doing so they also take in more energy than they actually need. As soon as they have recovered their deficiencies (their needs are again in balance) they will then temporarily eat less or even stop eating. After a while they eat normally again.
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The food must be biologically in balance. By this it is understood that all nutrients and other substances must be in the correct ratio to each other in each meal, and therefore must be present in the food.
Furthermore these must as far as possible be similar to the building blocks of the dog’s body. Because the dog is a so-called “energy eater” (which means that the amount of food that the dog eats depends on the amount of energy that the food contains), all the nutrients and other substances have to be in balance with the amount of energy in the food.
Nutrients are in the first instance divided into four categories, namely;
- A. Proteins
- B. Fats
- C. Carbohydrates
- D. Vitamins, minerals and trace elements
• A. PROTEINS:
Proteins are essential for the complete functioning of the body. Proteins are present in every cell of the body, as a fundamental component of the protoplasm (contents of the cells). An important condition relating to proteins is that they have to comply with very function-specific requirements. The most important functions of proteins in the body are; their function as a catalyst (enzymes), their regulatory functions (hormones), their protective function (antibodies) and not to be forgotten, their role in the build-up and function of the body (muscles, hair, etc). Because proteins form a very important component of a dog’s body (muscles) and because the total function of the body (metabolism), amongst others, is greatly dependent on the availability of the right proteins, this means that a certain portion of the food has to consist of proteins.
The building blocks of proteins are amino acids. Every protein has its own characteristic structure, the so-called amino acid chain, whereby the quantity and the internal order in the chain vary. These amino acids are further divided into essential (necessary) and non-essential amino acids. The essential ones are: Arginine, Histidine, Isoleucine, Leucine, Lysine, Metheonine-cystine, Phenylalanine-tyrosine, Threonine, Tryptophan and Valine. A certain minimum amount of each essential amino acid has to be present in the food, because the dog cannot make these itself out of other amino acids. This is in contrast to the non-essential amino acids. This is the reason that the value (the so-called biological value) per unit of protein is determined by the quantity of essential amino acids in relation to their total proportion.
In the end it is the amino acid that is the least present per unit of protein which determines the value of the protein for the dog (the rule of the minimum). Because the protein requirements of dogs are determined by the requirements for essential amino acids, the required protein content of the food is not determined by the quantity of protein, but by the biological value of the protein that is used. So the higher the biological value the less of it the dog needs, and vice versa. Furthermore the quantity of protein has to be in balance with the quantity of energy in the food; this means that the protein contents of the food must never be seen as an absolute amount.
For example: a dog of 35 kg needs each day approximately 1900 Kcal and receives the following amounts of protein per day;
Food A. with 4200 Kcal/kg and 24 % protein: the dog receives 1900/4200 = 452 g x 24 % = 109 gram protein.
Food B. with 3600 Kcal/kg and 24 % protein: the dog receives 1900/3600 = 528 g x 24 % = 127 gram protein.
Food C. with 4200 Kcal/kg and 30 % protein: the dog receives 1900/4200 = 452 g x 30 % = 136 gram protein.
Food D. with 3600 Kcal/kg and 30 % protein: the dog receives 1900/3600 = 528 g x 30 % = 158 gram protein.
(Kcal/kg = the amount of energy per kilogram of food).
Taking the above into account it should clear that we are not talking about an absolute protein content of a dog food, but about its so-called protein fraction. This is the percentage of the total energy in the food that is delivered by the protein.
And this can be calculated as follows:
The packaging states: “Protein 24%, Fat 7%, Cellulose 3%, Ash 7%, Water 10%”. Altogether this is 51% of the food, the rest, 100- 51= 49%, are the other carbohydrates.
1 gram protein delivers approximately 4 Kcal, 1 gram fat approximately 9 Kcal and 1 gram other carbohydrates approximately 4 Kcal.
The total energy per kilogram is therefore the sum of:
Protein 24% = 240 gram x 4 Kcal = 960 Kcal.
Fat 7% = 70 gram x 9 Kcal = 630 Kcal.
Other carbohydrates 49% = 490 gram x 4 Kcal = 1960 Kcal.
Total energy per kg: 3550 Kcal.
The protein fraction is therefore:
Energy content from protein = 960 Kcal divided by total energy = 3550 Kcal x 100.
So 960 / 3550 = 0.2705 x 100 = 27.05%.
The protein fraction of dry food is ideally around 22 – 25% for high-value protein materials and may not be more than 27% for puppies and growing dogs, otherwise the metabolism (liver) is placed under too much strain. If the protein content (total amino acids) of a food is higher than the dog requires this can have very adverse consequences for the dog. For example: through excess protein use or because of poor quality protein, too much protein is required in order to meet the requirements of essential amino acids. In growing dogs this affects speed of growth. Young dogs grow for example too quickly and unevenly. In this case dogs experience growth pains. These can lead to other problems and/or strengthen the effect of inherited problems, such as for example hip dysplasia, deformed back, twisted ankles and similar.
Because the excess and/or unusable protein, in the form of amino acids, still gets into the body via the blood, this has to be broken down in the liver to urea and then filtered out by the kidneys. In other words the liver and the kidneys have to “work overtime” in order to prevent protein poisoning, which represents an extra strain on these organs. Above all for young dogs this extra strain can be a serious problem (which often only becomes obvious at a later age) because the organs, just like the whole body, are in full-scale development and cannot yet work to full capacity.
Furthermore for young dogs these organs already have to process more than later as fully grown dogs, because their food requirements/intake per kilogram bodyweight is approximately twice as high than later as an adult. So one often sees that if food is given with a protein fraction that is too high (many of the so-called puppy foods) and/or poor protein quality, the liver cannot totally cope with “detoxification”. This can result in red spots with white heads on the sensitive skin areas (belly and groin). The skin is then used as an extra excretory organ. This means that a lot of skin problems already arise at an early stage. Furthermore these dogs are the candidates that later, in the second half of their lives, are given the advice by the vet to use a dietary or senior food (because the liver and/or kidneys can’t take it all any more).
Taking the above into account it will be clear to you why extreme care has to be taken in the choice of quantity and quality of the foodstuffs which provide protein. Only materials with a high biological value and of a quality that would be demanded in the human food sector, qualify in this respect.
• B. FATS:
Fats represent a concentrated form of energy and are important for the operation of muscles (movement) and the bodily organs. This energy also serves to keep the body temperature at the required level. Just like with amino acids in the case of proteins, for fats the content of essential fatty acids is important. These are: Linoleic acid, Arachidonic acid and Linolenic acid.
As long as there is sufficient Linoleic acid present in the food, Arachidonic- and Linolenic acid are less essential, because these can be formed from Linoleic acid. These are therefore in fact semi essential. If the food contains too few essential fatty acids, various bodily functions can be disrupted, such as the operation of cells and the build up and maintenance of the skin.
Just like essential fatty acids, lecithin is also a necessary component of fat. It works as a sort of emulsifier, without which the various fatty acids cannot be transported throughout the body. So lecithin is not an extra, but a essential raw material that must be present in every dog food.
Because fat is the easiest source of energy for a dog, whereby the organs are put under the least amount of strain (during digestion), a dry food must contain as much fat as possible. It goes without saying that these must be pure fats, which have not been heated to more than 90°C. These can only be found in the human food sector.
The so-called dry melted fats have been overheated (120 – 180 °C) and contain too many free fatty acids and polymers. Free fatty acids and polymers put strain on the metabolism (liver) and have amongst other things a negative influence on the health of skin, because they are stored in excess quantities in the skin.
• C. CARBOHYDRATES:
Carbohydrates are sugars and starches, and these ensure, alongside fat, for provision of energy, and are mostly derived from cereals. Carbohydrates are, just like proteins and fat, essential for dog’s health (this is in contrast to members of the cat family). Because of the fact that the dog’s intestinal tract is very short, the foodstuffs that the carbohydrates deliver have to be pre-digested. This occurs during so-called unlocking (comparable with cooking).
It is also possible to extrude the food when it has been prepared, but in this way the risk exists that the proteins, fats, and heat sensitive vitamins will be damaged. Above all fats and vitamins suffer greatly by heating above 100°C. In our opinion this is the reason why it is better to unlock the cereals first, before then adding them in a cooked form to the total composition, and then to press the complete mix instead of extruding it.
• D. VITAMINS, MINERAL, AND TRACE ELEMENTS;
Besides the proteins, fats, and carbohydrates, small quantities of minerals, vitamins, and trace elements are necessary. All these nutrients have to be in balance with each other. If too little of one nutrient is present in the food, symptoms of a deficiency will appear, not just symptoms directly related to the lack of the nutrient, but also others. This has to do with the fact that a deficiency of one nutrient can prevent absorption of another.
Also if there is too much of one nutrient other nutrients sometimes cannot absorbed, because they are tied in with the “excess”.
Some vitamins, especially from the B group, are sensitive to heating. This is one of the reasons why it is better not to extrude food. Loss of strands of hair can be traced back to damaging of heat sensitive vitamins in an extruded dog food.
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The food has to be made up in compliance with the guidelines of the Nutrient Requirements of Dogs. Throughout the world information from scientific research is exchanged, relating to dog food. From time to time the results of the various researches are discussed, summarised, and reported in guidelines. This is done by the “Committee on Animal Nutrition” (whereby the report on food for dogs is given the name “Nutrient Requirements of Dogs”). This is the reason that dog food must be formulated in compliance with these guidelines.
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The food must be free of added antioxidants and preservatives. Antioxidants are principally intended to improve the shelf life of a dog food, especially of the fats (to prevent them becoming rancid). The most well-known antioxidants are; BHT, BHA and Ethoxyquine, of which the last is the most dangerous (a poison used in farming).
Ethoxyquine is comparable with an assassin: One can be certain he is coming, but you never know when! So look carefully on the packaging, above all with dietary foods.
Antioxidants are, if good ingredients are used and the vitamins are expertly handled, unnecessary substances, at least in dog food. With good fats and high-value animal proteins, the redox-properties of the fat soluble vitamins are enough to ensure a long shelf life. Just to be sure there is, just like with human food, extra vitamin E and C added to good dog food, which leaves the body in the form of urine when in excess.
The danger with using antioxidants is hidden in the fact that these can seriously influence the metabolism. This influence can cause serious malfunction, which finally becomes detectable via skin and hair problems.
Given that the skin and coat are called the “MIRROR OF HEALTH”, this is sufficient evidence.
Preservatives are substances that prevent growth of fungi. Sometimes the packaging states “contains no preservatives”, and thereby the impression is created that there are no antioxidants contained in the food. However preservatives and antioxidants are two completely different things.
If the packaging reports “with E U approved antioxidant” without also stating the name of the antioxidant, you can be fairly sure that the maximum permissible quantity (150 mg/kg) has been added. Very often this hides itself behind the statement 150 mg/kg Ethoxyquine.
Because, amongst other things, of what is reported above, you have to choose ingredients in respect of which the same requirements are set for products intended for human consumption (even though these are much more expensive). This means, amongst other things, that the use of chemical antioxidants and preservatives is not necessary.
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The food needs to be free of proteins derived from soya products and/or other sorts of beans, because they contain so-called phytates (phytine and/or oxalic acid). These reduce the resorption/absorption of amongst others proteins, calcium, iron, zinc, magnesium and such like. Above all during the growth period this is observed, besides an incorrect protein balance and poor materials, as one of the reasons for a deformed back, twisted ankles, problems of stance and with walking, etc.
Of course there are also genetic factors that can cause such deformities, however we should not fail to achieve the things that are possible to be achieved by diet. Even if certain deformities are genetically present, the daily diet (particularly during growth) often determines whether these deformities manifest themselves later, and if so, to what extent.
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The food has to be free of destruction materials, because of the simple fact that in the use of these raw materials, it is necessary to also make use of antioxidants. (Since 1998 destruction materials may not be used in the EU any more in animal food, in contrast to for example the United States, Canada, Asia, and eastern Europe).
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The food must contain as much energy as possible per kilogram (Kcal.). Because the dog is a so-called “energy eater”, the dog eats as much as is needed to meet his energy requirements. So in other words, the digestion of other (food) substances is also dependent on the amount of energy in a particular dog food.
If a dog food is in good balance, but contains less energy per kilogram, the dog has to eat more of it. This means that the dog also has to process more unnecessary materials. These unnecessary materials all have to be metabolised by the organs. This puts the organs under extra strain, which above all can be a problem for young dogs, because the organs are still in development and are therefore still not working at full capacity.
Furthermore young dogs need twice as much per kilogram of body weight as adult dogs. Besides young dogs, this point is also certainly true for dogs upon which greater demands are being placed, causing the food requirements to increase, such as: working dogs, pregnant and feeding bitches.
If ingredients are used for which the same quality standards are set as for products intended for human consumption, this has the result that the energy content per kilogram can be very high. Namely with a value in use of more than 4000 Kcal per kilogram of food.