Even in early times probably way before the history of dogs was ever recorded, these pets were helping us for a variety of purposes, but they were mainly to hunt for food. But back in those days hunting was not a sport. It was serious and hard work.

Today the nature of a dog's job has taken on a different form. You will find he is still helping us in the search for food but this is normally for a different reason.

Every working dog's primary dietary need is increased by the energy he spends and no matter what the purpose or nature of the job he is given, his performance will always require some sort of time expenditure of energy. As a consequence, whenever dietary energy is increased, those B-complex vitamins, minerals, and the water necessary for burning the energy must also be increased.

Working dogs require most nutrients at no greater levels than non-working dogs. And if it wasnt for the increased need for energy and the nutrients to burn it you wouldn't have to do anything. However when working dogs eat large quantities of ordinary maintenance dog foods to obtain all of the energy they need, they will frequently consume some of the nutrients in excessive amounts. This may also cause them to eat such large quantities that the digestibility of all the nutrients in their diet are also adversely affected. Which will cause some nutrients to be obtained in inadequate amounts.

Working dogs simply cannot, physically, eat all of the food it needs to supply the required energy. When this happens the dog will suffer due to the lack of total digestible energy, and he will lose weight. If this condition is permitted to continue, your dog will stop working for you as his body just tells him too. This is really to the body acting so as to reduce its caloric demands. If you then force the dog to continue working at the same pace, it will lose weight faster and faster, and eventually its going to work itself to death.

Now Herd Dogs are the most common working dogs in the USA. They are also the same dogs that use the least amount of extra energy of any of the working dogs. You will very rarely find that then need to expend energy in excess of a normal dogs activity for any duration of time. Even their short-term expenditures of energy are not very great. The only time herd dogs ever utilize large amounts of energy are when they are rounding up stray cattle on a farm.