It is important to learn about social development of puppies so we can make sure we are meeting the needs of our potential service dog and shape him using this knowledge into a partner than can fit into the many different social settings we take him into.  The most critical piece in the success in service dogs is the dog has consistent people and environments that he is raised in. A change of people or environment during development and learning can significantly change the success of a service dog, especially if the changes occur during fear periods. In new situations, the dog must adapt to new scents, people, animals, objects, sounds etc without the support of his primary caregiver. Studies have shown that the primary caregiver can actually provide the dog with immunization in scary situations and the dog is more resilient in the presence of the known caregiver. A dog that changes people and environment several times over the course of training as a service dog is less likely to succeed. By getting a puppy and training it yourself, you are already ahead of program dogs for that simple act. 

There are three key phrases that are important to understand.

"Critical period” is defined as "a special time in life when a small amount of experience will produce a larger effect on later behaviour.” Coren. p. 143 and a

“sensitive period”. A sensitive period means “learning at one age is very easy but there is some small degree of flexility later on,…” Dogs seem to have both. 
“Socialization” is used to describe the”process by which an individual learns about his social world.” Coren p. 145  A pup starts learning the behaviours he needs to become a functioning part of a social group.

Social interaction starts for puppies at 3 weeks with their litter mates as soon as they start getting mobile and their eyes have opened. At that age, they start doing independent behaviours such as investigating their limited world of the whelping box.

Primary Socialization Period
 
Dogs have a primary social period that lasts from week 3 to 5. In this period, they can be introduced to any species. This early bonding is quick and strong.

Imprinting on people (kids to seniors) from 4 weeks of age for both scent, sight, sound, handling. To a puppy, each type of human is a different animal. The pup must learn that this broad range of ages and sizes and colours and clothing of people are all human and need to respond in a positive way. 
 

Social imprinting on other animals such as cats, birds, horses occurs in the same period. If introduced now, later puppies accept them as part of their social mix. 

Dogs do not seem to lose their own identity as a dog even when they are raised by humans and with other animals. They can form attachments to other species and know they are interacting with beings that are different than them. For this reason, it is important to introduce other animals such as cats, birds, rabbits, chickens and other animals they will later be expected to live with. 
 

Most dogs do not generalize well between species though.  Just because a dog is good with one bird does not mean it will be good with all. Chickens vs ducks, for example. They recognize individuals. A great example is how some dogs will recognize the family can and get along fine in the house, but when sees a strange cat, will chase and try to catch it or even kill it given the opportunity.  The secret is to socialize the pup to many different cats so it recognizes them as individuals but also as a species. 

At this point simple objects can be placed in the whelping box for the puppies to investigate. Paper towel rolls, boxes, and other one pieces items that are safe for the pups to interact with.  Between 5-7 weeks while still with the litter appears to be the best time to be introduced to new owner and people in general.

As the puppies grow, other common household items of different colours and textures like umbrellas, shoes, radios, plastic stools etc should be placed with the puppies and rotated daily. This helps them to learn that they are part of their normal physical environment. Since they are more mobile at this stage, different surfaces can be introduced (carpet, tile, grass, sand etc). Obstacles such as low bridges and a step for crawling on and crates added, tunnels, kids toys, tires etc. (see more about environmental enrichment in week 2 selecting a breeder). Jungle gyms with a variety of hanging objects and sounds can be added while the pups are supervised.

Tip:
Avoid puppies from small litters of three or less. There is not enough interaction with other puppies for them to learn dog language and bite inhibition. As well, dogs from single pup litters tend to not like doing the dog pile behaviour as adults and may be snappy when woken from a sleep. If the litter is raised with another litter of similar age, so the dog pile can occur, this may be remedied.
 

Secondary Socialization Period

Dogs secondary socialization period occurs between 6-12 weeks.
Puppies need to continue to be socialized thoughtfully and often to humans. This social “imprinting” changes the dog forever and is the foundation for adult behavior.
 Between 7 to 8 weeks, the mother loses interest in the pups, both for feeding mouths with sharp teeth and psychologically getting overwhelmed with the puppies. They increase the interaction between themselves to make up for this parental lack. This is when they learn 3 stages of warning: growl or lip lift, step and air snap, inhibited bite-contact with no pressure. At this stage they also begin learning emotional control (leave it, waiting etc). 

Robert Milner raises search and rescue pups amidst loud recordings of gunfire, bombs and similar sounds. The noise is continuous from the time the females become pregnant to the time they go to their new homes at 8 weeks or later. Pups climb over piles of rubble, swinging bridges and different surfaces as part of the feeding process. His gun dogs are introduced to gunfire at a distance in the first 6 weeks. This becomes part of their life experience. If these loud sounds are not introduced until after the fear period starts, the pup or dog perceives them as something to be fearful of.  

Until 8 weeks, pups are not fearful of anything. During that 8th week though, fear begins. Ray Coppinger tells us “Fear is in great part avoidance of novelty.”   After that, new things cause avoidance behaviours and take longer to socially acclimatize to. This is why it is so critical to choose a good breeder who takes time to socialize pups to other beings and environment that will be the same as pup will be spending his working career. 

By 8 weeks of age, puppies have memory of other individuals, and by 11 weeks, play patterns with others is based on size and activity level and previous history with those individuals. 

The peak of socialization for other dogs, animals and people is about 9 weeks since interactions at this time may have a bigger effect than any other time of the dog’s life. From here, the socialization window starts closing. 

Do be careful though.  Too much stimulation can be as damaging as too little, especially at the wrong time. A pup that grows up in a chaotic, unpredictable environment can become overwhelmed and this can produce an anxious adult dog. Pups that have been weaned too early and removed from litter develop extreme fearfulness around other dogs.

Studies show that pups removed from litter younger than 8 weeks are much more likely to develop dog to dog aggression when they are adults. In addition, they often become over attached to human, suspicious of strangers, protective of the person, and develop separation anxiety compared to puppies who stayed with the litter. 


By 12 weeks, the socialization period is closing quickly. Pups may start avoiding people, animals, objects they have never seen before.  It is worth noting that dogs that are removed from human or dog socialization after 12 weeks lose the benefits over time. For this reason, it is important to continue with socialization with people, animals, locations etc to 8 months or more. =16pxDogs raised in kennels to 12 weeks then in a house showed avoidance or aggression to people they did not know as adults. 

Fear Periods
Onset of fear period varies for different dogs. At 4-8 months the puppy becomes the equivalent of a teenager and forgets everything you taught him, yet he starts exploring the world more independently.  A growth spurt accompanied by hormonal stages cause them to act unpredictably. At this point, physical or psychological trauma can be long term as it has a huge impact on the puppy. This is not a good time to rehome a puppy nor is it a good time to have one spayed or neutered.
 

Not all breeds have the same time line for the critical period. In some it is as early as 12 weeks, while others, may be a long as 16 weeks but once that critical period closes, dogs have a poor ability to develop or change skills. However, a if a puppy is shy at 16 weeks, he will be shy all his life. There will be improvements, but the underlying temperament will always be shy.  That’s why starting with a pup at 16 weeks or older is not a good idea for a service dog unless you know extensive information about the pup’s early social and environmental history. Is he entering a fear period? Or is that his underlying temperament? 

As an adolescent and adult dog, it takes much longer for the dog to be desensitized to these people events and objects. Further, If their experience is negative the dog may never be comfortable with them. In the case of environmentally modified behaviors based on genetics, once turned on it may never be able to be turned off. An example of this would be allowing the dog to chase a rabbit, and in the process turning on epigenetic's for hunting. Good service dogs have a low prey drive to make this less likely to happen in this individual. 

Here is an article that explains the neuroscience behind brain development.

 http://www.simplybehaviour.com/the-neuroscience-of-critical-periods-if-you-are-thinking-of-buying-a-puppy-you-need-to-read-this-please-if-you-do-nothing-else-you-need-to-do-this-immediately-please/   

This article suggests schedule to get them comfortable with things. 

http://www.simplybehaviour.com/wp-content/uploads/2014/12/puppy-habituation-schedule-with-new-logo.pdf