Dogs are different from humans, and the German Shepherd isn’t like other dogs.
Proteins (meat, fish, eggs, etc), fats (vegetable and mineral), ballast (green vegetables), minerals and vitamins make up its diet, but to ensure that this is ideal we have to adopt a much more refined and scientific approach than that of a simple mixture of different food elements.
§ in addition, the nutritional requirements of the German shepherd, to reduce as much as possible the risk of well known diseases which it is prone to;
§ the physiological condition: growth, gestation, weaning, sporting activities and old age are some of the conditions that modify the nutritional requirements;
§ the state of health: in many cases, dietetics has become an important tool in the medical treatment of illness.
Health and Nutrition
Veterinary nutrition is a science that aims to identify, determine the role and the most effective dose of nutrients essential to the health and well-being of animals. It is a field where we are constantly acquiring fresh knowledge.
Every year a whole new batch of pet foods appears on the market, containing, besides essential health-sustaining nutrients, natural elements to prevent a number of risks of diseases and protect the body.
In the last 30 years, the food prepared by the major pet food manufactures has had the positive effect on the living conditions of our cats and dogs. It is estimated that the life expectancy of dogs, for instance, has increased by 3 years in the last 15 years.
From mere “survival”, giving the minimum required for the animal to stay alive, the concept of “diet” was developed, making for more beautiful and active pets. We have now moved on to the concept of “nutrition” thanks to an even more thorough knowledge of how the body functions and to the study of the benefits that our natural environment can contribute to health (plant extracts, certain minerals, different kinds of proteins etc.).
Nowadays, animal rations can be formulated according to specific needs, well identified deficiencies to be prevented or other specificities discovered by ongoing research.
Scientists and the major pet food manufacturers now acknowledge, the concept of diet has developed into that of prevention-nutrition and when necessary, health-nutrition or treatment-nutrition by preventing or curing certain diseases.
But our pets are threatened by another danger: human ignorance, compounded by man’s natural desire to do what’s best. The apparent “closeness” we feel between our four legged friends and ourselves leads us to believe that we know how they “function”. But such an anthropomorphic view merely reveals our lack of knowledge and we forget that they are carnivores. We project our own desires and lifestyle onto them without a thought about how different from us they actually are.
Human beings are omnivores, have a sense of taste, enjoy variety and attach a lot of attention to their food. It follows that it quite natural to think we are doing the right thing by giving our cat or dog a diet close to ours.
Wrong! Even nearly 10,000 years of domestication have not changed these carnivores into omnivores.
The size and shape of a carnivore’s organs are very different from ours. Jaws made for cutting and not chewing, no pre digestion with saliva but a disproportionate stomach to digest “preys” swallowed in a gulp, very short bowels (the larger the animal, the shorter the bowels) ill-suited to digesting most cereals…
Originally very active, these animals draw their energy from fat and have no so-called“cholesterol” problem but they can suffer from obesity (and its dire consequences involving the hart, joints, diabetes) if we do not manage to provide them with suitable diets or rations.
With dogs, food regulates behaviour: the same food, served in the same dish, in the same place at the same time is a guarantee to psychological equilibrium.
It is easy to see that is impossible to feed our pets adequately with food not very different from human food. It won’t be cooked enough; it will be too rich in carbohydrates, and ill-suited to their condition or morphology.
The same applies to all those small pleasures we so much enjoy and want to share with them.
A piece of chocolate (a poison for dogs in high doses), a sugar lump, a sliver of cheese, and a piece of bread and so on, all hose titbits ruin the perfectly balanced ration calculated by an animal nutritionist. An imbalance can lead to intestinal disorders and gradually impair the animal’s health.
The Nutritional Jigsaw
Fifty essential Nutrients
Dogs, like people are made up of hundreds of millions of cells that act as tiny power plants and provide energy for all life activities. These power plants, so necessary for life, constantly require fuel (food) and a combustion agent (oxygen) to produce the heat and energy that allow the dog to develop, grow and maintain a constant body temperature.
Feeding a dog well requires a through understanding of nutrition, which includes “all the processes involved in the exchange between organism and its environment and which allow the living being to assimilate foreign substances and to produce energy”.
Nutrients and their roles.
A nutrient is a simple component that must be present in a dog’s food in the proper proportions required for good health. The dog needs to each of the essential nutrients every day, because even though they cannot be made by the body, each has an important function in the bodily process.
Water the most essential nutrient of all
It may seem strange to call water a nutrient, but we can be certain that an animal will die after three days without it, although it will be able to go weeks without food. Water makes up two-thirds of a dog’s body and all of the tissues are bathed in it. For example, 80% of a muscle’s weight is water!
Proteins: the body’s building blocks
The main function of protein is to act as building blocks for the bones, muscles, nerve structures and all other living tissues. A protein molecule is mad up of both essential and non-essential amino acids. Different proteins have different nutritional values where digestion is concerned. “Good” protein (red or white meat, fish, eggs) is digestible, while “bad” proteins (tendons, connective tissue) are indigestible and will reappear in the stools. Even a highly digestible protein (one that is absorbed in the form of amino acids) will not necessarily be fully utilized (metabolized) by the dog. It may lack some of the essential amino acids, without which the dog cannot synthesize its own proteins. The “biological value” of a protein can be illustrated by a flag metaphor: the essential amino acids in a protein are like red, white and blue pieces of cloth. If there is enough of each colour of cloth, you can make an American or an English flag, but if one of the colours is missing, you cannot. In the case of proteins, synthesis stops when one “colour” runs out and the remaining amino acids are wasted. Remember that foods with high protein content are not necessarily of high quality. It is important to look at the types of proteins used (their balance of essential amino acids).
Finally, if the food is deficient in energy content, the dog will “burn” its own proteins for energy instead of saving them for building. The energy/protein balance of food is thus very important.
Fats: more than just an energy source
The main function of fats in food is to provide energy. Dogs digest fats very well-much better than humans do, in fact and like the smell and taste of fat (which means that they will eat too much fat if given the chance). However, this craving for fat should not be allowed to upset the nutritional balance of food.
Obesity can result, as in the United States, where about 50% of dogs are obese and France, where 25 to 30% of dogs are obese. (Medically speaking, “obesity” in dogs is defined as being overweight by 20%).
Chemically speaking, dietary lipids are long-chain esters of fatty-acids and glycol, of varying lengths and saturated to varying degrees. A food’s energy content is essentially a matter of fats it contains. In fact while glucide and protein exchange in dogs are essentially isocaloric, one extra percentage points adds fifty extra kilocalories per kilogram of food. An increase in the amount of fat, thus of the energy content, also makes the food more palatable. The temptation is therefore to add extra lipids to certain commercial or home made foods, to make the, more appetizing. The resulting possibility of over consumption requires great vigilance in the matter of portion size.
While dogs tolerate high fat foods very well, these should be given only to active dogs with very high energy requirements, such as lactating bitches.
Fats have very different fatty-acids contents, depending on their origins and thus do not all have the same nutritional value. In fact, fatty-acids have two functions:
-Non-specific, as energy providers. All fatty-acids contents have this function, but saturated fats from tallow (ruminant fat) or lard (pork fat) have only this function.
-Specific, namely structural and fundamental roles. Fats are part of all cell membranes are precursors of cellular transmitters and hormones.
Specific functions are carried by so-called “essential” polyunsaturated fatty acids, which the dog cannot synthesize and so must obtain in its food. There are to types of essential fatty-acids with which dog owners should be acquainted, in spite of their daunting names:
-The omega 6 series, which naturally occurs in vegetable oils more often than in animal fats (except poultry). A deficiency in these fatty-acids leads to dry, flaky skin, alopecia (hair loss) and dull hair. This is one of the most important nutrients for a beautiful coat.
-the omega 3 series, found mainly in fish fats, which is very important to the integrity of cell membranes and the functioning of the nervous system and immune system. Nowadays, these fatty-acid are also used for their anti-inflammatory properties (for treating many types of itchy skin) and oxygenating ability (they improve passage of oxygen into cells and the deformability of red blood cells, properties that are of interest for sport dogs and older dogs.)
Fats are particularly volatile ingredients that can break down rapidly. Rancid fats make foods less appetizing and can also lead to physiological problems for the dog, such as indigestion and pancreatic or liver problems. To prevent fats from becoming rancid, commercial dog food contains antioxidants. For homemade foods, avoid using cooked fats.
Glucides are nutrients found almost exclusively in plants. The basic elements of glucides are simple sugars with names ending in –ose, the most common being glucose the basic component of starch and cellulose. Other glucides, such as pectins and gums, are more complex molecules composed of uronic acids arising from oxidation of the simple sugars. Some of these glucides (such as starch and sugars) are digestible and can be assimilated by the dog, while the indigestible carbohydrates (also called fibre or cellulose) stimulate and regulate the p0assage of food through the instestine.
-Digestible glucides . Include lactose, which is important for puppies. Like all animals, dogs have a metabolic requirement for glucose, which is both a source of energy needed for certain organs such as the brain and a component required for the synthesis of many other biological molecules. Unlike most other animals, dogs can maintain their blood-sugar levels even if no glucides are present in their diet. They are able to use certain amino acids found in proteins for glucose synthesis. Thus, there is no risk of glucose deficiency in a dog’s diet.
-Lactose .Lactose aids digestion and absorption of nutrients. It also plays a role in synthesizing nutrients required for metabolism (ex. folic acid).
Bitch’s milk contains half as much lactose (the sugar found in milk) as a cow’s milk. Puppies do use lactose, but they have a limited ability to digest it, so over consumption always leads to digestive problems. When feeding puppies any milk other than bitch’s milk, it is imperative to take this into account and ensure that the substitute does not contain too much lactose. Adult dogs have an even more limited ability to digest lactose, so consumption of milk can lead to diarrhea.
-Starch is actually a complex of glucose polymers, which are branched to varying degrees depending on the plants from which they originate and are tangled into lumpy ball called a starch grain. Digestion of starch requires amylases, enzymes produced by the pancreas.
Starch can be made much more digestible by cooking it. It is found in grains (wheat, corn, rice etc.) and potatoes and provides quick energy if well cooked. Rice added to dog food should be sticky so that it is digestible and will not cause diarrhea. Two cooking processes are used for complete dry dog foods: extrusion (kibble) and steam flaking (gravy). Both processes ensure that starch is completely cooked and so is digestible.
-Dietary fibre is not digested, but is a requirement for dogs. Fibre consists of all glucides that are still undigested after passing through the small instestine: cellulose, hemicellulose, lignin, pectic matter, etc.
Fibre regulates the passage of food through the digestive tract, causing it to slow down or speed up as needed. Since intestinal activity depends on the dog’s stress level and the physical activity, the amount of fibre supplements added to the food should depend on the ultimate purpose of the food. Fibre also provides a substrate for fermentation by the bacterial population in the large intestine and helps balance it. For this reason, an abrupt change in the source of fibre can cause a transient disruption of equilibrium, with uncontrolled fermentation leading to flatulence and diarrhea.
While fibre is necessary for digestive health, it also has some disadvantages. It decreases the digestibility of a food and can reduce the digestive availability of some minerals through complex substances known as phytates.
Reduces digestibility of food can be taken advantage of, however, in foods for active dogs or in low-calorie diet foods for obese dogs. In this case, what is desired is reduced assimilation of food and a “diluting effect” so that the volume of the digesta will not be reduced too drastically. Selecting particular types of fibre can be optimizing this effect while limiting the disadvantages. However, it is still necessary to add certain nutrients to the food to offer decreased digestibility.
Minerals are highly interactive
Minerals comprise only a small fraction of a dog’s weight, however, their role is essential and their content in food must be carefully controlled. Furthermore, all minerals can affect the digestive or metabolism of other minerals, which means that it is essential both to ensure an adequate supply of each and to void any imbalance which could be even more harmful to the dog than mere deficiency.
Nutritionally speaking minerals are divided into two groups:
-Macronutritients, for which requirements are expressed in grams for an average dog. These include calcium, phosphorus, magnesium, sodium, potassium and chlorine.
-Trace minerals, for which requirements are expressed in milligrams (or less) per day. These include iron, copper, manganese, zinc, iodine, selenium, fluorine, cobalt, molybdenum, etc.
Quantitatively speaking, calcium and phosphorus are the main minerals required. They are major components of the skeleton and also have other important metabolic function, such as phosphorus’ role in energy transfers within the cell. The skeleton is a very important buffer reserve. The dog draws on this reserve if there is a deficiency, which explains why bone diseases appear when the phosphorus/calcium content of food is not balanced. Magnesium is also important in bone metabolism and along with potassium, is present in the intracellular liquid that is so important for many reactions.
Trace minerals are also essential to the creation of red blood cells and oxygen transport, to the integrity and pigmentation of the skin, to the functioning of enzymatic systems, to the synthesis of thyroid hormones, etc. Each plays one or more roles in the functioning of the organism.
Vitamins: not too many not too few
Everyone has heard of vitamins, a category that actually includes a wide range of substances essential to life. If any vitamin is absent or deficient in the diet, clinical symptoms of deficiency immediately appear and may lead to serious diseases in the long term.
As a group, the vitamins are distinguished by two characteristics.
-Unlike trace minerals such as iron, iodine or zinc, vitamins are organic substances.
-A dog’s daily requirement for each vitamin is expressed in milligrams or micrograms
Vitamins are found in food and can be ft soluble or water soluble.
Dogs need thirteen vitamins. Each has an important function, whether it be maintaining the skin’s integrity; facilitating good vision, normal growth and proper utilization of fats, or repairing blood vessels and nerve tissue.
Over consumption of certain vitamins (especially A and D) can be particularly dangerous. These vitamins are necessary and useful in the proper doses. In contrast, some vitamins such as E, seem to be very well tolerated even at high doses. In fact, high doses seem to be useful for curing and preventing cell membrane problems. No sign of vitamin E overdose has ever been discovered, so vitamin E content in excess of the physiological requirement may be an indicator of a quality food.
Finally, it may be remembered that brewer’s yeast is an excellent natural source of B vitamins and can greatly improve the appearance of the coat.
( with permission copied from the Royal Canin Encyclopaedia/Aniwa publishing)