Protein is one of the most important parts of dog food, as well as one of the least understood by the average dog owner. Most people have the misconception that the amount of protein the food contains is the important factor. However, the important factor is: How much of the food's protein can be used by the animal consuming it? To determine the amount of usable protein, we must first break protein down into its component parts. These parts are called amino acids. There are two classifications for amino acids of dietary protein;
(1) essential - those that the dog's own body cannot manufacture in sufficient quantities and
(2) non essential - those that the dog's own body can manufacture in sufficient quantities. It is the presence, balance and quality of the essential amino acids that determines the bio-nutritive value (% of usable protein) of the protein in a dog's feeding program.
All the amino acids, both essential and non-essential, have very specific nutritional jobs within the dog's body; such as the building of the muscle tissue, the regulation of antibodies within the immune system, and the
transfer of nerve impulses etc. The essential amino acids and some of their functions for a dog are:
This essential amino acid stimulates chaleceptokinin enzymes and thus is related to appetite control, increases
blood pressure in hypotension, works with minerals in skin and hair pigmentation, gives rise to Tyrosine, and produces adrenaline and noradrenalin.
This essential amino acid produces Serotonin that induces sleep, precurses the vitamin Niacin in treating and preventing pellagra, and is a vasoconstrictor that appears to aid in blood clotting mechanisms. Studies indicate a lack of tryptophan and methionine together can cause hair loss.
Listed above are the ten amino acids that are essential for a dog's dietary requirements. Note humans only require eight essential amino acids in our dietary intake, and for this reason a dog could starve if given the
same protein sufficient to sustain human life. Other factors to consider concerning a specific dog's protein requirements are:
(1) The age of a dog can change its protein requirements. Both puppies and geriatric dogs require lower amounts of protein and higher carbohydrate %'s in their food.
(2) The dog's activity level or stress level (due to environment or working conditions) can change its protein requirements.
(3) A bitch during the gestation and lactation period has her own very specific requirements.
(4)The other ingredients within the food can affect the amount of each amino acid required. For example, a food that is highly acidic (due to a preservative) can increase the requirement of the amino acid Methionine.