Four stages of puppy development

Early socialisation by the breeder/foster carer is crucial!

The four stages of puppy development are also known as sensitive periods. In the 1960s, Scott and Fuller investigated the critical period phenomenon. They found that there appeared to be definite critical periods for all aspects of social behaviour in all species and classified these periods by the major developmental step which begins (or ends) that period.

It’s important a pup gets a good start in life – from the time he is born – until the juvenile stage and beyond.

In a nutshell, here are the four stages of puppy development and how you as a pet parent can help your pup grow into a happy, well-adjusted dog.

Four stages of puppy development

PeriodLength (weeks)What's happening to the pupWhat you can do
Neonatal0 - 2Birth, suckling, cannot regulate body functions such as temperature and elimination.Provide a calm, comfortable and clean environment. Gentle handling by the breeder or foster carer can help the puppy’s ability to deal with stressors later in life.
Transitional2 - 3Eyes open, sight and hearing are limited. Tail wagging begins.Keep the puppy’s environment constant and safe to assist the pups to deal with their huge developmental change as they begin to stand and walk.
Socialisation3 – 12-14Startle to sound,
sight and hearing functions well. Interacting with his mother and littermates. Aware of the differences between canine and human societies.
In the early socialisation period, raise the litter indoors rather than in an outdoor kennel so the puppies can get used to the sights and sounds of household appliances, the comings and goings of different people and other domestic species such as cats.

Around 7 – 8 weeks, the puppy is usually handed over to his new family. Interactions should be closely supervised to ensure your pup is gradually exposed to as many things as possible. Positive experiences can produce a happy, well-adjusted dog from a genetically sound pup. Close supervision of interaction between children and puppy is crucial. This is an ideal time for puppy school and lay the foundation for future training
Juvenile12-14 – 26+Final maternal separation, distant explorationPups may begin to show a fear response to unfamiliar things. It’s important that pet parents continue careful exposure to new experiences or what you have achieved from early socialisation will be reduced.

Pups at this age sleep less so require greater supervision – many are surrendered to animal shelters at this age for normal puppy behaviour