Puppy growth stages
Birth to 8 weeks
The puppy is entirely dependent on its mother. Puppies are born with sealed eyes and ear canals. Walking begins at 16 days. Eyelids open at the age of 2 weeks, while ear canals open after approximately 17 days. Waste elimination without assistance from the mother (who licks the genital area to stimulate the process) begins at 23 days of age. At 25 days puppies begin responding to sights and sounds. Baby teeth appear at 4 to 6 weeks; consumption of solid food begins at the same time.
Little true learning is possible at this time, though some rudimentary socialization can be accomplished. For instance, frequent, gentle handling will help the newborn become acclimated to people. Remember that the puppy must remain with its mother and littermates during this important period. Only they can help it learn whats necessary for proper dog behaviour.
8 to 15 weeks
Full weaning takes place at or before 8 weeks. Puppies can be supplied with small amounts of solid food (as a supplement to milk) as early as the fourth week., when their first set of teeth will begin to emerge. Choose a specially formulated puppy food that is thinned to the consistency of gruel. As the weeks pass, the amount of solid matter in the gruel should be increased.
This is the prime time to learn to socialize with humans. Eight weeks is also the accepted time for a puppy to be removed from the litter and transferred to its adopted family. Crate training, Leash training, and house-training instruction can begin.
16 weeks to 11 months
Puberty begins at 6 to 8 months of age. A female dog will reach sexual maturity between the ages of 9 to 15 months; Males reach sexual maturity between 7 and 12 months.
At 12 to 20 weeks the puppy may become fearful if left alone or in new places. A puppy socialization class can mitigate the problem, which usually passes with time. Basic obedience-training are best accomplished at this time.
By the age of 1 year, puppies will have have made the transformation into adult dogs. In most cases, you will want to switch the dog's food from puppy-formula to a blend more suitable for adults.
The dog will be ideally fully socialized to humans and to other dogs at this point, and you may also notice an increased attention span. This is an excellent time to initiate advanced obedience training.