The Facts about Protein

Proteins are the essential parts of all living cells and they have many important functions. For one thing, they help build cell structures and muscle fibre. As you are probably aware, it is very important to eat enough protein so your tissues can grow and repair themselves properly.

But you may not realise that proteins also play a big role in other bodily functions, such as: regulating metabolism (as enzymes and some hormones); transporting essential materials around the body; and defending the body against disease. Protein is also a source of energy in the diet and will give the same amount of energy as its equivalent weight in carbohydrate.

What all this means for you as the owner of a dog, and the person who feeds him, is that you need to be aware of your dog's protein requirements. In this section, we'll go over the basic facts about protein, and then talk about how they apply to looking after your dog.

What are proteins?

Proteins are large molecules made up of long chains of constituent units called the amino acids. Only about 20 amino acids are commonly found in proteins. But hundreds or thousands of these amino acids may be arranged in any combination to give an almost infinite variety of naturally occurring proteins, each with its own characteristic properties. Like carbohydrates and fats, proteins contain carbon, hydrogen and oxygen. Among these nutrients, the element that makes proteins unique is nitrogen, a constituent of all the amino acids. This is why nutritionists often refer to "nitrogen balance" when they assess the protein status of the body. Two of the amino acids contain sulphur, which means this element is also found in many proteins.

Why dogs need protein

Animals need protein in their diet to satisfy two needs:

• to provide the essential amino acids that their own tissues can't make
• to provide nitrogen for making non-essential amino acids and other nitrogen-containing compounds.