Puppy Development by Week: 4 Puppy Development Milestones

The length of puppy development phases depends on [breed](https://www.masterclass.com/articles/dog-breed-guide), sex, and environmental factors. Puppy development differs from dog to dog, but general developmental processes and early-stage milestones exist. Learn about these phases and the development timeline in this outline: - __Weeks 0–2__: This is known as the neonatal stage. At this early period in a newborn puppy’s life, the puppy possesses a sense of smell, touch, and taste but cannot see or hear. Puppies in this stage have enough strength to pull themselves toward their mother, but not to stand up, and they cannot regulate their own body temperature. Mostly, neonatal puppies sleep and eat alongside their littermates against their mother’s body. - __Weeks 2–4__: Known as the transitional stage, at this point, puppies are growing and developing rapidly. A two-week-old puppy can take their first steps, begin to wag their tail, attempt to [bark](https://www.masterclass.com/articles/how-to-teach-your-dog-to-stop-barking), fully open their eyes, and begin to consume puppy food. They will also start showing signs of [social skills](https://www.masterclass.com/articles/how-to-socialize-your-dog) and personality but are still heavily dependent on their mother for warmth and sustenance. - __Weeks 4–6__: After a month, puppies will have more autonomy and exhibit a great degree of curiosity. They will begin to distinguish between humans and other dogs, find their role in the social order of the litter, and their [adult teeth](https://www.masterclass.com/articles/how-to-brush-a-dogs-teeth) may start to emerge. Breeders begin the weaning process during this period, and puppies will gradually eat solid food. - __Weeks 6–8__: Puppies at this stage are well into the socialization period. They can usually bark and may begin to venture outside the sleeping area, although they will tend to stay close to their mothers and littermates. They will also begin to learn bite inhibition from their mothers, essentially teaching them how to play-bite. - __Weeks 8–10__: Puppies are going through rapid learning and growth, particularly emotionally, beginning at the two-month mark. It’s essential to keep puppies from experiencing anything traumatic, as the fear response is deeply imprinted at this stage and can last for their entire lives. - __Weeks 10–15__: You can bring a puppy to a new home after ten weeks. They are relatively independent and more confident and comfortable in their environment but still susceptible to anxiety if overstimulated. They are likely to chew on everything, and supplying chew toys is good at this stage, as is beginning potty training and getting their vaccinations. - __4–6 months__: At four to six months of age, a puppy will have a distinct personality. Puppies will be more assertive and willing to test themselves and their environment, including other humans and dogs. Socialization is vital at this stage, as is house training. - __6–12 months__: Puppies transition from adolescence and reach sexual maturity between six and twelve months. They will lose their baby teeth as their adult teeth grow. Female dogs have their first heat, and male dogs will experience a surge in testosterone levels, which can manifest as reckless or stubborn behavior. It is essential to teach discipline during this phase. Careful socialization continues to be critical, as they will go through a fear period where new things will be threatening. While every dog is different, there are milestones that every dog owner should be aware of. This will help you know how your puppy is coming along on their journey to being a happy adult dog: 1. __Opening eyes__: Puppies are born essentially blind, and in the first week, puppies will barely open their eyes. By the second week, they should begin to gradually open their eyes. 2. __Walking__: Puppies will begin to show attempts at walking in the second week, and by the second or third weeks of age, they are usually taking their first shaky steps. 3. __Growth__: Puppies' growth rate is dependent on their sex and breed. There are some generalized tendencies among most major breeds. Usually, puppies will grow the fastest from the first three weeks to the first two months. After that, puppy growth tends to taper off as they reach the end of their puppyhood. 4. __Sexual maturity__: When a puppy reaches sexual maturity—in the range of six months to one year of age—you can take them to get neutered or spayed. Your dream of having a dog who understands words like “sit,” “stay,” “down,” and—crucially— “no” is just a [MasterClass Annual Membership](https://www.masterclass.com/) away. The only things you’ll need to train up a well-behaved pup are your laptop, a big bag of treats, and our exclusive instructional videos from superstar animal trainer Brandon McMillan. New puppies can be great fun to watch as they grow. Learn more about the different stages of puppy development.