Food of plant and animal origin contain vitamins, minerals, fats, carbohydrates, and proteins that become muscle and bone, nourish organs, and provide energy for daily living. People and other animals need nutrients in a particular balance to remain healthy and active, but some individuals of any species may have more energy than others because of the way in which their bodies process those nutrients. The process of processing, so to speak, is known as metabolism. The metabolism of all animals must function at a minimum pace to sustain life This basal metabolism rate provides the energy to operate and repair the heart, liver, kidneys, lungs, and other organs as well as the chemical reactions that allow the organs to send proper signals to each other. Below this minimum rate, the body begins to die.
Body temperature is maintained by an internal source of heat, a byproduct of basal metabolism.
While maintaining body temperature, providing for organ activity, and maintaining and repairing body systems, metabolism also produces enough energy for movement in response to stimulus the source of puppy antics, teen-aged dog shenanigans and adult dog Type A personality. Some dogs and some dog breeds have a naturally higher metabolism that causes a high activity level. These dogs can herd sheep, play ball, chase vermin to ground, follow horse-drawn carriages and horsemen, tromp upland fields and lowland meadows and swamps all day, or run like the wind at a moment s notice. Climatic conditions, disease, and nutritional level can influence metabolism. Dogs with metabolic imbalances such as hypothyroidism will be less active in all weather unless they are placed on medication to regulate the thyroid gland s output of hormones.