Puppy Development Stages

by Janice Jones     |Last Updated 04-23-2021

People often think of their small dogs as babies and themselves as parents.  Parents want to understand puppy development so they can predict what comes next. 

Just like human development, puppy development follows a predictable sequence, but unlike children, dogs pass quickly through these phases. 

Yes, puppies grow up fast.  In the wink of an eye, your little puppy will become an adult, so as a puppy parent, you don’t have much time to loose.

Small dogs, in particular, mature fast, much faster in fact than even large breed dogs.  By the time they are ten months old, many small breed dogs have achieved adult reproductive status and look and feel like an adult dog.

Nine Week old Puppy lying on the floorPuppy Development Stages

Experts cannot agree upon exact ages as some breeds and even dogs within breeds develop at different rates.  But the stages of development are predictable.

There are seven stages of puppy development not including the adult stage.

Puppy Development Stages

  1. Neonatal Period:  Birth to Two Weeks
  2. Transitional Period:  Two to Three Weeks
  3. Awareness or Identification Period:   Three to Four Weeks
  4. Second Awareness or Identification:  Four to Five Weeks
  5. Socialization Period:  Five to 16 Weeks
  6. Flight Instinct Period:  4-8 Months
  7. Second Fear Impact Period:   6-14 Months
  8. Maturity:  1-4 years

During the Socialization Period, there are several sub-phases

  • Curiosity:  5-7 Weeks
  • Behavioral Refinement:  7-9 Weeks
  • Fear Imprint/Impact:  8-11 weeks
  • Environmental Awareness:  9-12 Weeks
  • Seniority Classification Period  13-16 Weeks

Puppy Development Stages:  Neonatal Period (Birth - 2 weeks)

At birth, your puppy’s eyes and ears are closed.  In fact, only 3 senses are working—touch, taste, and smell and even then they are not entirely developed.  Puppies feel and respond to pain, discomfort and minor disturbances by whining or crying.

Their body temperature is well below that of a mature dog, and they are unable to tolerate a cold environment. 

Neonates have a body temperature of about 94 to 96 degrees F. The normal temperature for older puppies and adults is 101-102 degrees F. 

For optimal puppy development, the room temperature must be kept hot and breeders accomplish this by maintaining room temperatures around 80 degrees and providing heating lamps and/or heating pads. 

Puppies of this age are also incapable of either urinating or defecating on their own and depend on their mother to stimulate this process. 

Their first mission in life is to find warmth and food.  They have no teeth, but their nails are fully developed and some may even need trimming in the first week of life. Their primary activity at this time is to search out nourishment from their mom and sleep. 

Newborn puppies sleep most of the time, often as much as 90% of their time.  While asleep they often twitch and move only to re-position their body. 

Twitching occurs because at this point in their young lives, they sleep is the REM stage, a stage characterized by high brain activity. 

Beyond that, they have little interaction with litter-mates or the environment other than to huddle close to litter-mates and mom for warmth.   

The mother dog provides the warmth, the food, and cleans up after all pottying activity, a job that mother dogs accept happily. 

Puppy Socialization should begin the day he is born and continue throughout puppyhood.  It is up to the breeder to provide this type of stimulation so that the puppy becomes a well adjusted adult.

Barking is weeks away, but small vocalizations can be heard that resemble whining or crying.  Neonates will vocalize if they are being laid on, hungry, or in distress.

Puppy Development Stages:  The Transitional Period (2-3 weeks)

At around two weeks of age, the puppy’s eyes open and then several days thereafter, their ears open.  At first their vision is blurry but soon vision improves and the puppies can now see the world at least from their vantage point. 

Once their ears open they may begin to startle when they hear sounds.  Even from the very beginning, their range of hearing is nearly twice that of humans and into the ultrasonic range.

At three weeks of age, puppies become somewhat adventuresome and begin to move around more, though they are not very sure footed at this age.  This might be equivalent to the crawling stage in the human infant. 

Their eyesight and hearing are improving daily.  This is also the time that they begin to lap liquids and mouth solid foods if the consistency is mush-like.

They also begin to have limited interaction with litter-mates.   The majority of this interaction revolves around who is going to serve as a pillow and who is going to serve as blanket as they pile up in one small corner of the whelping box. 

Puppies take turns sleeping on top of the pile and cuddling underneath and don’t seem to mind either position.  They also begin to paw at each other and may try to bite at each others faces.

The initial eruption of teeth occur by the end of the period, but there won’t be enough teeth to manage hard kibble for several more weeks.

Sometime during this phase, they are able to eliminate on their own and will start to crawl out of their whelping box to eliminate.

Puppy Development Stages: 
Awareness or Identification Period (3-4 Weeks)

Three week old puppy in the Awareness Stage is learning to stand.Puppy Development Stages: Awareness

Now, the puppy has all of his senses and the environment takes on a greater meaning.  They become aware that they are dogs and have litter-mates.  They also discover that humans are part of their environment.

By four weeks of age, most puppies have figured out what “real” food is and continually eat more dog food, nursing less.  They are however, far from being weaned at this age. It is important to start them on a good high quality dog food..  Feeding puppies becomes the responsibility of the breeder.

They are moving around more and sleeping less. 

At four weeks, he is also beginning to regulate his own temperature and feel the urge to pee and poop on his own.  He won’t always need Mama to stimulate him to go potty, yet most good moms continue to clean up after their pups at least for a while. 

If given an opportunity, puppies will pee or poop on a puppy pad. 

A little play-fighting emerges within the group.  Puppies discover their voice and vocalizations become louder.  A small bark can be heard for the first time and some will also begin to howl. 

Puppies still struggle to nurse, but mama often makes herself scarce.  A small growl or a show of teeth by the mother lets the puppies know what discipline is all about. 

Nevertheless, nursing can continue up to 10 to 12 weeks in small breed dogs.

Puppy Development Stages:
Second Awareness or Identification (4-5 weeks)

A young five week old puppyPuppy Development Stages: Second Awareness

The gentle sibling interactions of last week turns into a much more rigorous play that includes growling, chasing, and wrestling. 

They discover toys and will investigate any new object placed in their path.  They will grab a small object and run with it, chew on it or use it in a tug of war game with a litter-mate. 

If given the opportunity, they will develop problem-solving skills and learn how to cope with a little frustration. 

By now, the puppies are feeling very confident in their familiar environment.  A pecking order develops but may change from day to day.  The alpha dog on Tuesday is not the same one on Wednesday.  But, when puppies are taken away from their safe place, a totally different personality develops. 

Some become frozen with fear at first, and others venture out with zeal.  Most are somewhere in the middle, cautious at first, but then curious and interested in their new surroundings. 

Puppy Development Stages:  Socialization Period (5-16 weeks)

Two Mal Shi Puppies with their mother.Puppy Development Stages: Socialization

By five weeks of age, he has reached the toddler stage of puppy development and will become very busy interacting with litter mates and of course humans.  

Mama will try to encourage her youngsters of this age to wean, making herself less available for free drinks at any time of the day.  Some moms actually regurgitate food for their young, although this is not seen very much in domestic dogs. 

At six weeks of age, puppies are ready for their first shots and they should have already had a couple of wormings by now to deal with internal parasites.  The tiny breeds may not get their first shots until around the age of 8 weeks.  Their play takes on new dimensions and toys become fascinating objects. 

Puppies want to explore and will find ways explore every inch and cranny of their allotted space.  During this period, breeders should continue to offer stimulation in the form of sounds, smells, and textures and provide exciting environments for puppies to explore.  Mama continues to teach her puppy manners especially “bite suppression.   

Puppies learn what appropriate canine behavior is and is not through the use of play and observing other canine body language. These actions will be repeated for two weeks until they become fully weaned and ready to go to their forever home. 

Smaller breeds such as Yorkshire terriers, teacup toy poodles, and Chihuahuas may need more time with mama and the litter mates.  A puppy of 6 weeks is curious, friendly, outgoing and fully ready to learn.  If socialized correctly he will be completely ready and eager to please his new human family when that time comes.

But beyond the confines of the puppy pen lies a whole new world that they must learn to master.  Socialization during this period is critical for normal adult functioning. 

Researchers have shown that the brain atrophies if a dog is raised in an environment void of sensory stimulation.  The more enriched the environment is during this stage, the better able the puppy will do as an adult. 

According to Pat Hastings, editor of Puppy Development, socialization does two things for the puppy.  First it reduces the number of things a pup might become frightened of and it provides the experience of being frightened and then recovering.  Under socialized puppies grow up to be adult dogs that are shy, fearful, unable to discriminate threats and even become aggressive.

Socialization is a continuing process that should last a lifetime, but it usually doesn’t because people are busy, there are limited places a dog is allowed to go and places that do allow dogs are often filled with pathogens that cause disease.  Good protection in the form of immunizations will help protect dogs from serious diseases.

The socialization period is further divided into distinct sub-catagories.

Puppy Development Stages:  Curiosity Period (5-7 weeks)

The video above was made for my other website, but shows the development of the puppies pictured on this page.  They are called Mal-Shi and are one half Maltese and one-half Shih Tzu.

Puppies have little sense of fear now and will want to investigate everything.  Climbing on, crawling through and tasting everything in their path.

Puppies readily accept people with little fear.  Temperaments are beginning to emerge and some breeders will use temperament testing such as the Puppy Appitude Test developed by Volhard. 

Puppy Development Stages: 
Behavioral Refinement Period (7-9 weeks)

A small puppy is exploring his immediate surroundings.Puppy Development Stages: Behavioral Refinement

At eight weeks of age, many small breed puppies are ready to go to their new home. Others will stay with their canine mother and breeder for another 4 weeks.  This applies primarily to the smallest of the toy breeds. 

The puppy has an extremely short attention span but a fully function brain, capable of learning anything.  At eight weeks of age, the puppy is a small version of what it will look like as an adult. 

Many breeders, in the U.S. at least agree that it is the best time to go to their new home.  Whether a puppy goes to a new home at eight weeks or remains with the breeder depends on who is the best equipped to socialize and train the puppy at this most vulnerable stage.

Puppy Development Stages: 
Fear Imprint/Impact Period (8-11 weeks)

At eight weeks, the puppy begins to experience caution in his action.  At previous stages of puppy development, he was exuberant and reckless, charging forward without any fear. 

During the next couple of weeks, the puppy becomes cautious and checks everything out.  It is important that new owners let nature take its course as the puppy will get through this stage and move on relatively quickly and unscathed.   

It is also important that owners not “cuddle and baby” the puppy during this time, but rather assure for the puppy’s safety, but not jump in to rescue them unnecessarily. 

Some puppies develop fear and anxiety issues if allowed to be “saved” during this time that are hard to correct later on. Naturally, if a puppy is in danger of being harmed, quick intervention is important.

If the puppy goes to his new home during this time, the first few nights will be hard for the little guy as he has not had too much experience being on his own.   

If frightened during this period, it might take weeks to return to normal. 

Many people argue that this may not be the best time for home changes, traumatic visits to the vet, shipping, or harsh discipline. Rather this is the time that the puppy should be exposed to many positive experiences.

The more new sights, sounds, and smell, that he can experience the better but within a safe environment.  Puppies that have lots of socialization experiences and stimulus during this period will be much better equipped to handle change as they grow. 

Sometime around eight weeks of age, the puppy is ready for their first immunizations if they were not vaccinated at six weeks of age.  They should already have been wormed for intestinal parasites.

Puppy Development Stages:
Environmental Awareness Period (9-12 weeks)

A small puppy is standing up on his back legsPuppy Development Stages: Environmental Awareness Period

Bonds become very strong during this phase.  If the puppy spends most of his time with his litter-mates, he will bond very closely with them and have a difficult time spending time with humans.  Their dog to dog social skills will be strong, but show shyness or fear around people. 

If there time is spent bonding with humans and separated from other dogs, the human bond is strong, but the puppy may not develop good skills with other dogs.  Ideally, a mix of human and dog interaction is the most beneficial for the puppy.

As new owners take on the responsibility of dog parents, they often wonder how big their puppy will get. Most purebred dogs fall within a framework that helps the owner know what to expect.  Even within the same litter, however, there can be variation. 

I found an interesting resources that helps you predict what your puppy's height will be as an adult.  At the Puppy Height Calculator, you can learn how to measure your puppy's height and it will let you know how tall they are full grown.   

Puppy Development Stages: 
Seniority Classification Period (13-16 weeks)

This is considered to be the puppies “tween” stage because the first signs of independence are noticeable.  We call this the preteen stage in human development.  This is a very demanding stage of puppy development and the well-behaved little guy who stuck right by your side will suddenly want to ignore you and do his own thing. 

Behavior is a bit erratic during this period and tends to fluctuate from being a sweet, cuddly baby to a stubborn teen.  Teething begins in earnest and the puppy tries to find anything and everything to chew upon, whether it is a favorite wooden chair or a person’s toes.  A puppy might bite for the first time in an effort to do his own thing. Having a puppy-proofed house is important during this phase.

This is the time when potty training usually occurs and beginning obedience training such as how to walk on a leash, not necessarily how to heel.  It is also a time when the puppy must learn what is expected of him. It is never too early to begin informal basic command training.  If he’s allowed to “bite” because it doesn’t hurt, dominate other pets, or resist human interactions such as nail clipping.  If these important lessons are not learned, it will be more difficult later on correct bad behaviors.

Some behaviorists believe that end of the socialization period (4 months) effectively closes the window of opportunity for the puppy to benefit from these early attempts at socialization:  skills training, exposure to many different things, people and places and learning right from wrong.

Puppy Development Stages: 
Flight Instinct Period (4-8 months)

As the name implies, this period spells an abrupt change in your otherwise small, lovable (“Velcro”) dog.  As with human teenagers, puppies feel the need to test their wings and will wander farther away or may even take off unexpectedly while off leash. 

Now, this wouldn’t pose a real problem if there were no dangers and the puppy came immediately when called. 

The perfect recall is rarely achieved during this period.  Puppies remind me of the old folk tale, the Gingerbread Man.  If you have an especially fast breed, the chances are that he could be a city block away before you realize he’s taken off. 

Attitude is everything during this adolescent period.  The dog tries to break all the rules if given the opportunity and test the limits. People often call their dog stubborn, disobedient, and testy. 

Fortunately, this phase does not last long.  For some, it goes on for days or weeks, but rarely does it last a month or more.  Even the low energy breeds go through this stage, so knowing that it will happen can help you prepare.  A long leash outside or one of those retractable ones will keep him near you and away far from harm’s way.

Run, run, as fast as you can, you can’t catch me,

I’m the Gingerbread Man!

(ahhh, I'm the PUPPY!)

A small puppies is running as fast as he canPuppy Development Stages: Flight Instinct

Puppy Development Stages: 
Second Fear Impact Period (6 to 14 months)

This period is hard to define.  The puppy may go through it during a time of rapid growth or may occur when the puppy encounters a new situation.  It is likely that the onset of sexual maturity and the surge of sex hormones may have something to do with this phase. 

A happy dog that loves people suddenly fears them.  The dog that walked easily into the veterinary clinic, suddenly rebels pulling forceful away from the door.  The dog that seemed fine one day, reacts poorly to some imagined fear. 

Beyond the fear issues, the period from six months to 14 months also heralds in sexual maturity.  Girls go into heat for the first time and can mother a litter.  Boys will show interest in female dogs, lift their leg to urinate and may mark urine inside and out.  They may also hump or mount other dogs or objects including humans.

Final adult teeth come in and finally set in the jaw at about 8 months.  This brings on a new chewing frenzy.  You thought your puppy was through with this stage when it starts up again and this time those teeth can cause some real damage.

By one year, any problematic behaviors that have not been eliminate will set in and the effort needed to  remove those behaviors will be much greater.

The end of this period marks the end of puppy-hood and the beginning maturity for small breeds.  Small breeds will reach their full adult size, height and weight.  Some breeds will see changes in coat colors and thickness. 

Even after maturity and long thereafter, the activity level may go down slightly.  But many small breed dogs tend to keep the playful puppy personality long into their senior years.  Gradually, the exuberance of youth will begin to fade.  

If you have done your job of training and socializing your puppy, your adult dog should start to calm down and become more predictable in habits and behavior.

I hope this quick introduction to Puppy Development Stages has been helpful, but may I suggest the following resources if you would like to probe deeper into this subject.

References and Recommended Reading about Puppy Development Stages

Another Piece of the Puzzle: Puppy Development

Before and After Getting Your Puppy: The Positive Approach to Raising a Happy, Healthy, and Well-Behaved Dog

The Art of Raising a Puppy

About Janice (author and voice behind this site)

Having lived with dogs and cats most of her life, Janice served as a veterinary technician for ten years in Maryland and twelve years as a Shih Tzu dog breeder in Ohio.

Her education includes undergraduate degrees in Psychology with a minor in biology, Early Childhood Education, and Nursing, and a master's in Mental Health Counseling.

She is a lifelong learner, a dog lover, and passionate about the welfare of animals. Her favorite breed for over 50 years has been the Shih Tzu, but she has also lived with Poodles, Maltese, Yorkshire Terriers, Beagles, English Bulldogs, Carin Terriers, and a Cocker Spaniel.

When not writing, reading, and researching dog-related topics, she likes to spend time with her eight Shih Tzu dogs, husband, and family, as well as knitting and crocheting. She is also the voice behind Miracle Shih Tzu and Smart-Knit-Crocheting

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