Puppy Socialization and Learning


One facet of developmental behavior is the process of socialization. Socialization of young animals has a remarkable influence on the subsequent behavior patterns as an adult. An understanding of the socialization process will provide insight into the origin of normal adult behavior patterns. The possible causes of inappropriate behavior are better understood with prior knowledge of possible causes of the behavior. Knowledge of the socialization process and development of behavior also provides information on the proper methods of rearing young animals so adult behavioral problems may be prevented.

Socialization of Dogs

The dog has evolved as a pack animal with strong instinctive behaviors that enhance the survival of the pack even over that of the individual. The pack structure requires the dog to develop social behaviors that support a dominance hierarchy and are compatible with many individuals living in close contact most of the time. Puppies thrive on social contact, requiring constant supervision, interaction and training to develop socially and to relate properly with other pack members. In packs of wild canids the pups are never left alone and adult pack members spend at least 85% of every day in contact with other members.

The dog has developed into one of our finest companion animals precisely because of its need for social contact and because a dog is able to substitute humans for companionship. Most behavior problems emerge when the pack social system is either absent or fails to train the pup in proper social development. Barking, howling, whining, digging, chewing and attempts to escape are all natural behaviors that increase the likelihood of a pup being found and reunited with its pack should it become accidentally separated. Dogs can be taught to accept short periods of social isolation without triggering instinctive separation anxiety and resulting behaviors. The key here is that dogs need to be taught to accept this abnormal situation and the dog must be confident that it will be reunited and supported by its human pack most of the time. Unfortunately, most people do not understand the evolutionary development of the dog and its innate and essential requirement for social contact. In the absence of leadership from members of its human pack many dogs will assert themselves and eventually interpret absence of leadership as submission and will develop dominant behavior traits. This can lead to serious behavior problems including aggression, vocalization, nervousness, over protectiveness and fearfulness.

Dogs do not thrive but suffer in isolation. They require social contact preferably with other dogs and humans. A dog should not be left alone for long periods of time during either the day or night. If a dog has to stay at home alone it needs companionship. The house becomes the den of the pack or family and can provide a dog with a sense of security making it easier to train a dog to stay alone for short periods in the house. A crate when used properly greatly facilitates this process. When the dog is put outdoors alone, when the family is away, the dog experiences feelings of both isolation and abandonment. Separation anxiety causes the expected behaviors and can lead to community animal behavior complaints not to mention a miserable pet.

Most people when educated about a dog's social needs will do what is necessary to move the dog into the home to interact with the family, provide another dog for companionship when left alone or will place the dog in a more appropriate living situation and get a cat.

Socialization Stages

Primary socialization is the process whereby the young puppy forms initial social relationships with other individuals, including human beings. These social relationships change as the puppy matures and are associated with four distinct periods of development: the neonatal period, the transition period, the socialization period, and the juvenile period. Each of these periods is closely related to structural and functional changes that occur in the nervous system as the puppy matures.

Neonatal Stage

In most breeds of dogs, this period extends from birth to two weeks of the age. During this time, the puppy has social interaction with its littermates. Most of the mother-puppy interaction is related to nourishment and warmth since the puppy is completely dependent on the bitch. This is understandable, since the neonatal puppy lacks many of the sensory and motor capacities necessary for complex social activities. The newborn is functionally blind and deaf but has a good sense of smell. His major sensory capacities appear to be thermal (heat) and tactile (touch) perceptions, while motor activities are limited to crawling, suckling and distress vocalization. Because of these sensory and motor restrictions, the puppy's social behavior is minimal. Ingestive behavior is limited to suckling. Eliminative behavior (urination and defecation) occurs primarily as a response to abdominal or anogenital stimulation by the bitch.

The neonatal pup exhibits preliminary exploratory behavior in the slow crawling movements while turning his head from side to side. This response is noted when the puppy is trying to find the mother's nipple or some other warm object. All other social interactions of the puppy are achieved through care seeking behavior. If the puppy is hungry, cold, or hurt, he gives a series of rapid whines until comforted by the bitch or human handler. Because the puppy cannot hear or see, handling is important during this stage.

Transitional Stage

Dramatic changes occur from 15 to 21 days of age, characterized as neonatal behavior transitions to the beginning of sensory, motor, and psychological capacities common in adult behavior. This transition varies from a state of complete dependence upon the bitch to one of relative independence. During this time the puppy's eyes and ears become functional, allowing him to respond to visual and auditory stimuli, while his motor system has matured sufficiently to permit the puppy to stand, walk and chew. A change also occurs in the learning abilities. At the end of the transition period, the rudiments of adult social behavior patterns emerge, e.g., the puppy wags its tail at the sight of people or other animals and begins to play actively with his littermates by biting, chewing and pawing. The puppy also develops control of urination and defecation and begins to eliminate outside the nest area if allowed to do so.

In summary, during the transition period, the puppy's behavior undergoes a rapid transition from the neonatal state of total dependence on the bitch to recognizable adult behavior patterns.

Socialization Stage

Although some of the social interactions occur during the first three weeks of the puppy's life, major social interactions and attachments develop later. The socialization stage extends from 2 and ½ weeks to 13 or possible up to 16 weeks during which the puppy acquires almost all of the adult sensory, motor and learning abilities. During this stage the puppy forms its primary social relationships and attachments that define its future social partners. At this stage the puppy can form non-canine specific attachments and learns appropriate canid specific behaviors.

The experiences of the young puppy during the socialization period will have the most dramatic effect on ultimate adult behavior. For this reason, we refer to this stage of socialization as the sensitive period of development. Early in the socialization period, the puppy's behavior is related to care seeking activities, including a search for food, warmth, and comfort. It forms a strong attachment to the bitch and tries to follow her if she moves around the cage or pen. Distress vocalizations are exhibited when the puppy is isolated for brief periods in a strange place. In addition, it may show a fear response to strange objects or people during the first week of the socialization period, and may hide, growl, or run away.

While in this period, the puppy begins to lap up and drink liquids and chew on solid food. The eruption of teeth aids in the chewing activities and also plays a role in the development of antagonistic behavior patterns. Puppies begin chewing and biting one another in playful fighting activities, sometimes growling at one another in mock battle play or when in competition for food or play objects. This competitive behavior plays an important role in the establishment of a social hierarchy or dominance order. The owners of the puppies can recognize which puppies will be the dominant and/or aggressive ones and which ones will be timid and/or submissive.

Other social activities are seen in the form of early pack or group-coordinated behavior. If one puppy leaves the home area, the others will usually follow. The puppies begin to explore and investigate their environment. They will first approach objects cautiously and may give a startled response to strange objects. A puppy will gradually become accustomed to his new environment and will venture further from his home area. This process is also seen in the puppies' eliminative behavior. Early in socialization, the puppy defecates and urinates close to his nest or cage. As the puppy matures, it gradually goes farther from the cage and eliminates in specific spots. When the puppy needs to defecate, he will usually run to an area, wander around with his nose to the ground, and then circle rapidly. Most pet owners do not realize that this is the ideal time to housebreak a puppy.

Procedures used to housebreak puppies have permanent influence on the subsequent elimination behavior. In wild pack animals, the mother will regurgitate meat outside the den for the pups to eat. Eating stimulates defecation and the pups begin to associate eating, playing and elimination behaviors. This information needs to be available to the breeder who can use these natural behaviors to form appropriate, lifelong patterns that virtually eliminate house-soiling problems. At three weeks of age, most pups cans climb over a one-foot high barrier. The breeder can block off the front of the litter's crate or use a one-foot high nest box. This will insure that the neonate pups are confined for their protection. When able to climb over the barrier, it is time to take them outdoors for short periods of time for exploration and play. By 4 to 5 weeks of age pups will eat solid food and when fed outside are encourage to associate elimination with going outdoors. Feeding them outside lets them eliminate on the ground and confining them when indoors prevents inappropriate elimination.

Pups will sleep between play and feeding periods so the attentive breeder can get them outside after each of these activities. Confinement in individual crates at night around 5 to 6 weeks of age will begin to introduce weaning and independence while still in the proximity of their littermates and dam. As pups approach weaning at 5 to 6 weeks of age, they need to be fed individually, ideally in their crates and then allowed to play and sleep together during the day. At this time, when prospective owners are choosing their pup, have the new owner bring a stuffed toy, that resembles the pups, that can be left with the litter and put in with the chosen pup at night in its own crate. This stuffed toy, which smells of the litter, will provide companionship and comfort to the pup as it transitions in its new home.

As the socialization process progresses, there is a gradual change in the young puppy's social interactions. In the fourth week, the puppy interacts primarily with his mother and to a limited extent its littermates. The young puppy learns about care-giving behavior even though it may be months before this behavior pattern is elicited. This may be important in female puppies because they may learn some of the behavioral activities appropriate to maternal care. This period is also a sensitive one since severe emotional and social stresses at this time apparently have a lasting effect on the puppy. The way the bitch or human handler responds to a puppy's vocalization of distress and general behavior may determine how the puppy reacts to stressful situations later in life. Taking a puppy away from its mother at this time is certain to cause poor socialization.

Studies with rats have shown that enriching the neonate's environment with obstacles, which can be explored, leads to greater agility and cognitive function in adults. Puppies also benefit from exposure to inanimate articles and socialize more easily when handled by humans. Rolling puppies on their backs and holding them gently for a few minutes while handling their feet or touching them all over makes teaching puppies to accept restraint without fear easier. (See Puppy Rearing by Peter Vollmer)

By the fifth week of age, the puppy has increased social interactions with littermates as evidenced by play behavior, running together and fighting or dominance behavior. This type of behavioral activity is seen from the fifth through the seventh week of life. The time span is referred to as the critical period of socialization. In a sense, the puppy must learn to be a dog. Young puppies isolated from their littermates during this interval frequently have difficulty, later in life, socializing with other dogs and may show abnormal sexual behavior as adults. A female may be unwilling to accept a male, or a male may not know how to react to a female in estrus. These represent extreme reactions, but we should be aware of them when mating problems occur.

Coinciding with this time of socialization to other dogs is an increasing responsiveness on the part of the puppy towards humans. Interactions with humans usually begin around six weeks of age. This has several important functional and practical considerations. At this time, the bitch normally weans the puppies and they become more independent. This is also the time when the puppy's nervous system reaches the structural and functional capacities of the adult. In other words, the puppy is ready to learn and will do so quite readily. Six to eight weeks of age is an ideal time to place puppies in their new home so further socialization with humans and subsequent housebreaking and training can occur.

Puppies have to experience circumstances they will see as an adult between 8-12 weeks of age. Unfortunately, many dog breeders and potential dog owners fail to realize the importance of obtaining a puppy at this age. Puppies obtained too early will be too "human oriented" and puppies obtained too late will be too "dog oriented". Pups can be placed as early as 6 weeks of age into homes with other dogs because they will continue to socialize with these new dogs and there is a benefit to the puppy becoming exposed to different types of dogs early on. Care needs to be taken to protect the pup from trauma from unfamiliar dogs in the new home. The more novel situations pups are exposed to the better the confidence and less the stress when novel situations are presented later in life. Pups socialized at 3 months without further socialization until 6 to 8 months may become fearful. Therefore it is important to continually reinforce socialization beyond the socialization stage.

The socialization stage is one in which the puppy forms many new social relationships. These relationships can generally be divided into three specific periods: · Socialization to the mother · Socialization to peers · Socialization to humans.

Socialization to the mother

During the socialization to the mother period, we can say that the puppy learns compassionate care from its mother during this first period. If there is disruption of this period, the puppy may not learn or develop good maternal instincts. More importantly, it may not learn to care for and show concern for its human companion.

Socialization to peers

During the second stage, the puppy learns to speak "dog", this means he learns to say "hello", he learns the "body language" and how to respond to other dogs. Without this development, the puppy will be fearful or aggressive towards other dogs. This is exemplified by the dog, which barks at all other dogs and seeks its owner when other pets approach, as opposed to the normal greeting and sniffing that goes into saying "hello" in dog. Dogs also use a complicated set of behaviors to say "I'm dominate" or "This is my territory" or "I'm submissive" or "I'm in heat" or "Let's play" and so on. Without this period, dogs become illiterate about their own language. Hand-reared puppies may not have appropriate canid social behaviors. Kennel isolation can result in extreme fears to new and novel situations.

Socialization to humans

The final sensitive stage of the socialization period is when pups learn to speak "human". They learn not to fear the touch and embrace of a human. They learn not to be afraid of the human speech. If puppies are not raised with human interaction during this period, it is unlikely they will ever trust a human or at least result in fear of strangers. These pets will be wild and "dog oriented".


The time from the end of socialization (twelve weeks) until sexual maturity occurs defines the juvenile period. The time of this period varies in duration with the breed of the dog. During this period the dog refines existing skills and the learning abilities are adult-like. Behavioral activities and further socialization of the young dog depend largely on his environment. The young dog left in the kennel during this time develops quite differently from the dog that matures and grows with a human family. In either environment, the most important process during this time is developing its social status. The pack's survival depends upon cooperation and development of a defined dominance hierarchy for each of the pack members. The pack will not survive if members squabble over position during a hunt. This hierarchy is established through individual interactions from the time the pups first encounter other pack members. Dogs learn to interpret and communicate with body language. Although dynamic and evolving, the dominance hierarchy is stable and reinforced by subtle body language and vocal cues that reinforce each member's position. The leaders of the pack develop through challenging and dominating others.

A young dog left in a kennel with several littermates or other dogs of similar size or age may fight over food, water, or play objects. At other times spontaneous bouts of aggression of one dog towards another may occur. These usually occur until a dominance hierarchy is established. The young puppy that is placed in a home becomes a part of the social organization of the family and will try to establish its position in the dominance hierarchy of the family through play and daily interactions.

There is little doubt that the young dog will test the members of the family until he finds a place in the home. New pet owners need to understand this is when many behavioral problems arise. The untrained or undisciplined puppy at this time may become aggressive or destructive. When this occurs, carpets are chewed or wet, chairs destroyed, drapes ruined, doors broken, and many other obnoxious things occur. These events frequently lead the novice dog owner to deposit their new pet at the city pound, dog shelter, or the pet may be abandoned in a rural area. This happens all too often and contributes to the large number of unwanted dogs in our towns and cities. The human/companion animal bond suffers greatly from misunderstanding and miscommunication during this period. It is during this period that owners need to understand and demonstrate leadership with the new puppy. Leadership behaviors include: eating first, sleeping in the best place, entering and exiting through doors first; initiating and stopping play and teaching the puppy to accept restraint and handling. The "alpha rollover" is also effective in establishing dominance of family members over the puppy. (This procedure is described later in this text. Also, see Recalcitrant Rovers handout and Puppy Rearing by Peter Vollmer). If new pet owners understand that a puppy will constantly test them, they can alleviate many of these behavioral problems.

It is necessary for the owners to understand that the puppy is going to spend a lot of time exploring his environment, and if left unsupervised, he may inadvertently ruin some household objects. The owners should show the puppy which areas of the house are open for exploration. In most cases, it is advisable to give the young dog something to play with and/or chew on to avoid any damage to items of value. It is best not to provide multiple play toys so that the puppy can distinguish between its toys and non-acceptable items. We suggest a rubber chew toy such as a Dental Kong and a sock with a knot in it and a t-shirt with a knot in it. Puppies can distinguish between items of clothing when a knot is placed in the center of their toy.

New owners should also be made aware of the puppy's possible reaction when they leave the house since the young dog may become frightened or lonesome, thus causing some damage. It is essential to keep a puppy in a place where they cannot damage things in the owner's absence. Puppies need to be crate trained. (See Dog Independence Training Tips Handout or check out the Animal Care Library of our website at: http://www.mckenzieanimalhospital.com/pet-resources/animal-care-library.htm). As soon as the puppy has been trained and can be trusted, the puppy can be allowed access to the entire house. This typically takes 4 to 6 months. Thus, the new owner must make it clear that the dog must obey the rules of the house. Any other alternative usually leads to problems. Puppies should not be left confined for long periods unattended. This period of socialization is greatly facilitated when there are other well-adjusted dogs in the home or when an owner can be at home with the dog.

If a puppy is supported by the presence of other dogs or humans during this period, it is also important to teach the puppy to adjust to social isolation. Take the dog on short trips, errands, visits to friends and family and for outing to dog parks with and without the other dog(s). Training classes are excellent to strengthen the bond between owner and puppy and increase the puppy's confidence and security. Use a crate to transport the puppy and provide a rawhide chew or biscuit when left alone for a few minutes. Be calm with departure and return so the pup does not get excited.

Effects of Isolation on Socialization

While the social aspects of behavior in the puppy have been noted, it is equally important to see how alterations of the normal socialization process can modify subsequent adult behavior. The term critical period becomes meaningful here since this is a time in the puppy's life when many or all aspects of its behavior are particularly susceptible to modification. Simply stated, it is the time when the early experiences of the puppy will have the greatest effect on the subsequent behavior of the adult dog.

Puppies socializing between six and eight weeks respond to human beings much better as adults than puppies allowed socializing before or after that time. Puppies that did not receive any socialization with man during the critical period were essentially unapproachable and untrainable as young dogs and adults.

Hand-reared puppies have been socially isolated from their littermates. These puppies show great deficits in social behavior and in reactions to their own species. These puppies are non-vocal, non-oral, non-aggressive and passive with other puppies. They rapidly become aggressive towards their peers following socialization and rarely engage in-group play. They tend to wander off alone and engage in self-play or to manipulate inanimate objects. Some of the hand-reared pups become aggressive enough to achieve dominance over their peers. Although hand-reared puppies are socially attracted to humans, they do not show the affection towards humans that is normally seen.

Early socialization is extremely important in dogs destined for specific jobs. Investigators studied the effects of delayed socialization on the trainability of guide dogs. All puppies received a limited amount of socialization to humans for the first twelve weeks of their lives. Following this time, the puppies were placed in private homes at varied times. Some puppies were placed immediately at twelve weeks of age; others were isolated for one, two, or three weeks respectively before being placed in the private homes. Of those puppies that were placed in private homes at twelve weeks of age, 90% became guide dogs. However, when similar puppies were isolated for two weeks following the initial twelve weeks of socialization, only 57% were successfully trained as guide dogs. Furthermore, if puppies were isolated for three or more weeks, only 30% were successfully trained. Therefore, social deprivation after the critical period of socialization may result in the young dog's becoming asocial. This often occurs in large breeding kennels where it is a common practice to let dogs mature before training is begun. The majority of these dogs may make decent hunting dogs, but they tend to hunt for themselves and pay little attention to the handler. Some dogs that are reared in this manner develop a syndrome referred to as "kennelosis." They exhibit timidity and will run from strangers. They may in fact show fear responses when someone tries to catch them.

There is a critical period of socialization for young puppies, and to deny a puppy this experience will have lasting effects that may severely alter the normal adult behavior of a dog and render it incapable of forming appropriate social bonds either to humans or to other dogs. It is to be hoped that more dog breeders will become aware of the critical period of socialization and will raise litters of puppies in such a manner that proper socialization occurs. If this is performed conscientiously, it will undoubtedly reduce the incidence of maladjusted dogs and dissatisfied pet owners in today's society.


A great source of information on puppy behavior is available at Dog Star Daily

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