Protein Quality

Dogs' diets may not follow the food ingredient pyramid, like humans', but dogs do need a variety of nutrients, including protein, fat, fiber, vitamins and minerals. Protein accounts for about 50 percent of the dry matter in a dog's body and is an essential component of every cell in the body. It is important in body structure, such as in muscle, hair, bone and organs. Plus, protein is critical in functions, including carrying oxygen in the blood, defending the body against infections and digesting food. The dietary protein not utilized in support of these areas can be burned as energy.

Although protein is considered necessary for healthy dogs, it is not actually protein that is used, but rather the amino acids of the protein. A protein molecule contains thousands of amino acids. Digestion breaks down the protein molecules into amino acids. The amino acids are then absorbed and distributed by the bloodstream to the body cells, which rebuild the amino acids into body components.

The quality of protein depends to a large extent upon its amino acid content. The body can make some amino acids, while others, called essential amino acids, must be supplied by the diet. Ten amino acids considered essential to dogs are histidine, isoleucine, leucine, arginine, methionine, phenylalanine, threonine, tryptophan, valine and lysine. Diets that furnish a proper balance of essential amino acids have quality protein.

The absence of even one amino acid will influence how dogs utilize the rest. Protein deficiency symptoms, which are actually amino acids deficiency symptoms, include depressed appetite, poor growth, loss of weight, rough and dull haircoat, impaired immune function, irregular estrus, lower reproductive performance and reduced milk production.

Dog foods providing the proper amounts of essential amino acids in an available form supply good-quality protein. The combination of two or more protein sources in a dog food generally provides a balanced amino acid profile. A balanced ratio of plant protein with another plant or animal protein can provide all of the essential amino acids dogs need.

To ensure that you are feeding your dogs quality protein, follow these guidelines:
1 Feed a food manufactured by a reputable manufacturer, such as Ralston Purina Company. Dog food manufacturers remain reputable because they provide nutritionally balanced dog foods that include the proper amounts of protein with the essential amino acids.

2 Check to see if the manufacturer conducts ongoing pet nutrition feeding studies. Studies at facilities such as the Purina Pet Care Center help manufacturers design specific foods to help dogs develop and grow properly.

3 Call the manufacturer. Most dog foods have a toll-free number on the package, and they can help you select a dog food that meets the needs of your dogs. For example, consumers reading a bag of Pro Plan? brand pet food know to call 1-800-PRO-PLAN for more information.

4 Look for the words, "Animal feeding tests using AAFCO (Association of American Feed Control Officials) procedures," which are associated with the nutritional adequacy statement on the label. This shows that the nutrition in the product has been proven complete and balanced for the intended life stage.