Puppy Development: From The Humane Society Web Site
Birth To Two Weeks - Neonatal Period
- Puppy is most influenced by his mother.
- Senses of touch and taste are present at birth.
Two To Four Weeks - Transitional Period
- Puppy is most influenced by his mother and littermates.
- "Eyes open, teeth begin to come in, and senses of hearing and smell develop."
- "Puppy begins to stand, walk a little, wag tail, and bark."
- "By the fourth or fifth week, eyesight is well-developed."
Three To Twelve Weeks - Socialization Period
- "During this period, puppy needs opportunities to meet other dogs and people."
- "By 3 to 5 weeks, puppy becomes aare of his surroundings, companions (both canine and human), and relationships, including play."
- "By 4 to 6 weeks, puppy is most influenced by littermates and is learning about being a dog."
- "From 4 to 12 weeks, puppy remains influenced by littermates and is also influenced by people. Puppy learns to play, develops social skills, learns the inhibited bite, explores social structure, ranking, and improves physical coordination."
- "By 5 to 7 weeks, puppy develops curiosity and explores new experiences. Puppy needs positive ""people"" experiences during this time."
- "By 7 to 9 weeks, puppy is refining his physical skills and coordination, and can begin to be housetrained. Puppy has full use of his senses."
- "By 9 to 12 weeks, puppy is refining reactions, developing social skills with littermates (appropriate interactions), and exploring the environment and objects. Puppy begins to focus on people; this is a good time to begin training."
Three To Six Months - Ranking Period
- "Puppy is most influenced by "playmates," which may now include those of other species (people, other pets)."
- "Puppy begis to see and use ranking (dominance and submission) within the household (the puppy's ""pack""), including humans."
- Puppy begins teething (and associated chewing behavior).
- "At 4 months of age, puppy experiences another fear stage."
Six To Eighteen Months - Adolescense
- "Puppy is most influenced by human and dog "pack" members."
- "At 7 to 9 months, puppy goes through a second chewing phase, part of exploring territory."
- "Puppy increases exploration of dominance, including challenging humans."
- "If not spayed or neutered, puppy experiences beginnings of sexual behavior."