Nutrients are the building blocks of all living things. They allow both survival and growth. The nutrient requirements of a dog vary with: age, stage of growth, activity, stress, genetics etc.
There are two categories of nutrients:
Macronutrients are needed in large quantities. They are the sole source of energy (kiloJoules) and are the basic building blocks of nutrition.
Micronutrients are required in smaller amounts and include:
trace or micronutrients.