When puppies are first born and for the first three weeks of their life, their total awareness is confined to their sense of smell. Their eyes do not open for at least two weeks and it is often three weeks before their sense of hearing is beginning to come into play. Consequently, their whole existence is limited to the knowledge that they glean from their sense of smell. Even these first few weeks can have an impact on the puppies' training. For example, if the pups are kept in an unclean environment or small confinement where the dam has no chance to keep a clean bed area for her pups, this will sometimes carry through into later life and a puppy will be more difficult to housetrain.

Puppies who are exposed to light stress in this period of time seem to have a better ability to withstand stress later in their lives. Changes in the environmental temperature, being handled, being moved about...these are "stressors" for the young puppy. Breeders who routinely clean the whelping area, removing the puppies while cleaning out the area, picking them up, weighing them, are also actually improving the puppies ability later in life to adapt to changes.

The period of three weeks to six weeks is the most opportune time for the puppy to develop true "dog behaviors". Puppies who are removed from their littermates before six weeks often do not learn dog behavior. When they are with littermates, they are taught what a bite is and whether they are biting too hard. They are taught what a growl means and what will happen if they ignore a growl. In short, they are taught manners by their littermates and their dam. These manners will be important to them all the rest of their lives when they interact with other dogs.

After the third week and all through the growing up in the whelping area, puppies should be exposed to as many different environmental stimulation as possible. Surfaces they can walk on that are wobbly, things they can smell and bounce around with their noses or their paws, things that make noise, things that they can climb on...all are important for the tactile, sensual and emotional development of the dog. Imaginative breeders will fill the lives of the puppies with such stimulation, knowing that in the end it will provide for a well-balanced animal that can adapt to many different situations and remain a stable personality.

Puppies often go through what some behaviorists call a "fear stage" at about eight to nine weeks of age. This developmental stage seems to be a time when puppies will be affected more strongly by occurrences that may startle them or frighten them. Puppies who have already been heavily exposed to lots of stimulation in their environment are much less likely to be influenced by unusual or traumatic events during this "fear stage".

Taking all of this into consideration, one can see that the choice of a puppy's breeder can be important in the choice of a puppy. Prospective "parents" of a new puppy would do well to evaluate not only the new puppy but the breeder of the puppy and seek out a breeder who has some knowledge about the early developmental stages of the puppy.