CreamofBritish ASD Australian Labradoodles UK

The Five Critical Stages Of Puppy Development

    There is so much to know about taking care of a puppy, there is also much to understand about training a puppy.

How do you begin? You begin by first learning about what makes a puppy a puppy – what he needs, what he responds to and what he can do.





















                                                        This then is your introductory course – in basic puppy.

                                                                        THE FIVE CRITICAL PERIODS.


Scientific studies have shown that, there are five critical periods in a puppy’s life, that is five phases of mental development during which adverse conditions can cripple a dog emotionally without hope for recovery.

Conversely, positive conditions during these five phases of emotional growth can produce dogs of the highest calibre – mentally and socially. So important are these findings, that guide dog foundations instituted these ‘positive conditions’ for puppies being raised to become leaders of the blind.

Dogs trained to lead the blind receive the most rigorous and exacting training of any dogs and therefore must be perfectly adjusted.

Dr Paul J Scott, Director of  Animal Behaviour at Roscoe B Jackson Memorial Laboratory at Bar Harbour , Maine, directed a project to determine just when these critical periods took place.

The consequences of a person’s failure to acknowledge and respond to these critical periods were demonstrated in one particular test. A puppy 21 days old, was removed from the litter and completely isolated.

Although the puppy was fed and watered, the caretaker was careful not to play with or speak to it. The only toys experimental puppy had were his water bucket and dish.


By 16 weeks of age the puppy had no contact with other dogs ( except during the first 21 days of its life) and no human contact except the caretaker.


At four months of age the experimental puppy was once again placed with his litter mates. He did not recognise them, either as litter mates or as dogs!


His isolation during the critical periods of his life – his complete removal from the companionship of dogs and humans – had marked his character to the extent that he could not adjust to animal or human society.

0 - 20 days First Critical Period

As a result of many years of scientific research, it has been determined that the first critical period covers the entire first three weeks of a puppy’s life, 0 to 20 days.


During this period a puppy’s mental capacity is nearly zero and the puppy reacts only to its needs of warmth, food, sleep and it’s mother.


Tests were carried out to determine whether a puppy was capable of learning anything at all during the first critical period, it was determined that it is not.














Scientists found, however, that something nearly miraculous happened on the 21st day and it occurs in all dogs, regardless of breed, on this day all of a puppy’s senses begin to function. The senses were present in the puppy during the first critical period bet were dormant. The 21st day marks the beginning of the second critical period.


During this period the new puppy needs its mother more than at any other time. The brain and nervous system begin to develop. Awareness begins to take place and in the mental state, a puppy’s experience can be rather frightening.


A puppy removed from its mother during this second critical period will never attain the mental and emotional growth that it could. During the second critical period the social stress of being alive has its greatest impact on a puppy. No other time in a dogs life is so crucial to emotional growth.


It is during the second period that the characteristic of nervousness can generate shyness and other negative qualities in a puppy. Once negative characteristics have been allowed to develop ( during second period) no amount of

reconditioning or training later in life alter the negative characteristics.

29 - 49 Days (4-7 wks) Third Critical Period

At this age puppies will venture away from the nest – although not very far- and so do a little exploring. At the beginning of a puppy’s sixth week, the awareness of society will dawn, that is, the society of man and the society of dog.A puppy’s nervous system and his trainability are developing and by the end of the third critical period will have developed to capacity. Unfortunately some dog books say that a puppy has the brain of an adult at the conclusion of third critical period. This is not true and research proves it. Therefore a more comprehensive look at what takes place during this third critical period is certainly in order.


During this period a puppy will learn to respond to voices and will begin to recognise people. A social ‘pecking order’ will be established among the puppies in the litter. Some of the puppies will learn to fight for their food and will learn to be bullies. The litter mates that are cowed by aggressive tendencies of the others will become shy.


The scientific tests at Hamilton Station have shown that it is advantageous for a puppy to remain with the litter long enough to acquire a little competitive spirit but that too much is detrimental to the puppy’s emotional growth. The pups that remain in the litter after the seventh week will begin to develop bullyish or cowed tendencies – which will remain with them into adulthood. The longer a puppy remains with the litter after completing the seventh week of its life, the more deteriorated the emotional growth of that puppy will be.


At the end of the third critical period, the puppy is considered emotionally developed and ready to learn. But the puppy does not possess an adult brain at that age. 

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21 - 28 days (3-4 wks)Second Critical Period