When to Get a Puppy
Aside from the obvious answer — not before you are ready — the time to get a dog is when you have completed your doggy education. And when the pup is ready.
An important consideration is the age of the pup. Most puppies change homes at some time in their life, usually from the home where they were born to the homes of their new human companions. The optimal time for a puppy to change homes depends on many variables, including his emotional needs, his all-important socialization schedule, and the level of doggy expertise in each household.
Leaving home can be traumatic, and limiting the pup's emotional trauma is a prime consideration. If the puppy leaves home too early, he will miss out on early pup-pup and pup-mother interactions. And since the first weeks in a new home are often spent in a doggy social vacuum, the developing puppy may grow up undersocialized toward his own kind. On the other hand, the longer the puppy stays in his original home the more attached he becomes to his doggy family and the harder the eventual transition. A delayed transition also postpones all-important socialization with the new family.
Eight weeks of age has long been accepted as the optimal time to acquire a new pup. By eight weeks, sufficient dog-dog socialization has taken place with mother and littermates to tide the puppy over until he is old enough to safely meet and play with other dogs in puppy class and dog parks. Yet the puppy is still young enough to form a strong bond with the human and canine members of his new family.
The relative level of doggy expertise in each home is a vital consideration in determining whether the puppy is better off staying longer in his original home or leaving earlier to live with his new owners. It is often assumed that breeders are experts and owners are rank novices, so that it makes sense to leave the pup with the breeder as long as possible. A conscientious breeder is usually better qualified to socialize, housetrain, and chewtoy-train the puppy. When this is true, it makes sense to get the puppy when he is older. (In fact, I often ask novice owners whether they have considered a socially mature and well-trained adult dog as an alternative to a young pup.)
This of course presupposes the breeder's superior expertise. Unfortunately, just as there are excellent, average, novice, and irresponsible owners, there are also excellent, average, novice, and irresponsible breeders. With the combination of an experienced owner and a less-than-average breeder, the puppy would be better off moving to his new home as early as possible, certainly by six to eight weeks at the latest. If you feel you are a qualified puppy raiser but the breeder will not let you take your pup home before eight weeks of age, look elsewhere. Remember, you are searching for a puppy to live with you, not with the breeder. In fact, you might be better off looking elsewhere anyway, since a less-than-average breeder probably produces less-than-average puppies.
Adapted from BEFORE You Get Your Puppy by Dr. Ian Dunbar