Protein: What it Is & Why Your Pet Needs It


Protein comes up a lot in the dieting world. We know it's a type of energy lower in calories, but it actually has a much more integral function than just fueling us up - it's one of the building blocks of life. That's why it's important to make sure that your pet is getting all the right kinds of protein he needs.

So what is protein?

Protein is an essential nutrient that has numerous functions in the body, including muscle growth, tissue repair, enzymes, transporting oxygen in the blood, immune functions, hormones, and providing a source of energy. A protein is defined as a group of amino acids linked to each other in different quantities and sequences. Each protein is a unique combination of amino acids and the arrangement of these amino acids is what determines the specific function of a protein. Dietary protein that is digested in the stomach and small intestine is broken down to its individual amino acids that are then absorbed into the bloodstream. Amino acids travel to various cells of the body where they are used to build body protein structure.

Essential vs. Nonessential

Over twenty amino acids are involved in building different types of protein in the body. Essential amino acids are those that cannot be formed fast enough or in sufficient amounts to meet the requirements for growth and maintenance and, therefore, must be supplied in the diet. Nonessential amino acids are those that the body can produce in sufficient amounts from other nutrients and metabolites and, thus, do not need to be supplied in the diet.

Although essential amino acids are not stored as such in the body for any significant period of time, they are constantly metabolized. Consequently, they must be provided simultaneously in the proper proportions in a pet's diet. The essential amino acids for dogs include:

- arginine
- histidine
- isoleucine
- leucine
- lysine
- methionine
- phenylalanine
- threonine
- tryptophan
- valine

Cats require the same ten essential amino acids plus one additional, taurine.

Which foods are sources of Protein?

Protein comes from both animal and plant sources. Most ingredients contain inadequate amounts of one or more amino acids, which makes them unable to be used as the only source for meeting protein needs. However, by careful selection and combination of different protein sources, the pet's protein needs can be met. For example, soybean meal and corn gluten meal complement each other perfectly, because the amino acids that are deficient in one are present in the other. Neither meat nor plant protein sources are complete on their own; however, either can be adequate if fed in combination with another complementary source of amino acids.

How do I know if my pet isn't getting enough protein?

If you feed your pet any Purina ONE SMARTBLEND formula according to our recommended feeding guidelines, you can feel confident your pet's protein needs are being met. 

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