8 Stages of Puppy Development

A puppy’s education begins from the moment of its birth. A pup’s mother teaches it how to interact with her, with littermates, and with other dogs. While they are still with their mother, puppies begin to understand the hierarchy of group life. During this time, the mother dog is also teaching them how to eat, defecate, play, and how to be alone for periods of time, as well as other important social skills.  

Most pups leave the litter and begin living with a human group when they are about 2 months old. At this point, humans must pick up where a pup’s mother left off. When you bring your pup home, you will teach him how to behave in your home, how to interact with humans, and how to follow your lead. A puppy class is a good start, but in order for your dog to be well-mannered and behave appropriately in all situations, you must continue training through all stages of your puppy’s development.  

Neonatal Period:  Day 1 through Day 14   

During this period each puppy is completely dependent on its mother; all social interactions are with her.  Mom takes care of all her pups’ needs for food, grooming, and nurturing.  During this period, handling the pups can stress both mother and pups. For this reason, the pups should should usually be handled only by professionals: a breeder, veterinarian, or trainer.  

Transitional Period:  Day 14 through Day 21   

During this period pups begin to show individual personalities.  They begin interacting with littermates as well as with their mother. The puppies are attracted to movement and new environments and objects.  Each puppy begins to exert his or her Independence and become inquisitive.  

Initial Socialization Period:  Day 21 through 7 weeks  

During this period, puppies can begin to form bonds with other species (such as humans). Pups can identify their own species and begin to identify future social partners.  Pups are able to interact with littermates, adult dogs, and humans. They play with toys, play fight, and show increased eagerness to explore. In some pups, this new confidence approaches fearlessness. Puppies in this stage can begin to eat soft food in addition to the mother’s milk. Although pups are manifesting signs of independent personality and motivation, they should not be removed from the care of their mother until at least the end of this phase. 

  • Puppies should be touched and held during this phase so that the pups learn to view humans as a species with which they can form social bonds.   
  • They should be exposed gradually and carefully to new sights, sounds, toys, and experiences.  
  • They should begin eating soft foods. 
  • They should experience some supervised play with other puppies, adult dogs, and humans. 

Early socialization is tremendously important in the development of well-adjusted puppies. A pup’s interactions and experiences during these weeks provide the foundation from which he will learn how to communicate with other dogs, respond to humans, understand hierarchy, and behave appropriately and safely when interacting with adult dogs. 

Socialization/Interaction Period:  7 weeks through 12 weeks  

During this period puppies are separated from their mother and littermates to begin life in a new home. At this age, a puppy’s main drives are to eat and to play. Some pups develop a fear response to new surroundings and objects that may be stronger than the attraction response that manifested in the preceding weeks. For other puppies, the social motivation to make contact with new surroundings, objects, humans and other animals may very well overcome any wariness. Either way, controlled socialization with other animals, humans, and other dogs is vital at this stage of development. Puppies should experience gradual and careful exposure to new environments and experiences. 

It is most important that pups at this stage learn to establish strong relationships with humans vs. other dogs. Especially during this stage, your puppy should get the majority of attention, affection, and interaction from you.  Establishing yourself as the primary provider for all his physical and social needs is an important foundation for establishing your leadership role. 

  • Ideally, crate training, house breaking, and leash training should begin during this stage.  In addition, introducing grooming during this stage will continue teaching your dog to accept gentle handling and will reinforce your leadership role. 

Near the end of this stage, at around three months, puppies will begin losing their “baby teeth.” They will seek out things to chew to relieve the discomfort in their mouths.  You will need to watch your pup whenever he is not contained to ensure that he does not chew valuable, personal, or dangerous items. 

  • Bring your puppy everywhere that you can, but be careful not to bring him to loud places or areas where there is too much going on.  Don’t push him into situations that will make him fearful. 
  • Always have your pup’s crate with you.  If he is afraid, you can place him in his crate and he can watch from his “safe place” until he becomes accustomed to the people and noise.  Once he is desensitized, you should be able to bring him out comfortably 
  • Stay alert to situations and surroundings when you are out with your pup so that you can prevent negative socialization meetings. 
  • Don’t allow your pup to be passed from person to person. The feeling of insecurity from the potential of being dropped will make meeting new people a negative instead of a positive experience. Instead, allow your pup to remain on the floor and let him choose to approach as many or as few people as he is comfortable with.   Remember, as humans we are giants to young puppies.   
  • Provide safe and durable chew toys, such as Nylabones or bully sticks, for your puppy’s teething needs. 

Juvenile Period: 3 months through 4 months At this stage, your pup’s attention span is short, but he is able to learn and retain. Food and play remain important motivators, but he is also ready to respond to appropriate correction. In earlier stages, he learned to accept his subordinate role to his mother, the basics of interacting respectfully with other dogs, and to accept human handling and interaction. Now, he must learn his subordinate role in the hierarchy of your home–his place in his new “pack.”  

Your pup will continue to teeth during the beginning of this period. Most pups have all their adult teeth by the age of eight months, but this timetable can vary depending on size and breed. 

  • Continue crate training and housebreaking. 
  • Continue basic skills training, such as walking on a leash. 
  • Continue to provide safe and durable chew toys for teething. 
  • Continue to be the primary source of interaction and play. Limit play time with other dogs. Make sure any interaction with other dogs is kept positive and that your puppy is never dominated or corrected inappropriately by other dogs. 
  • Correct unacceptable behaviors, such as mouthing, jumping, or aggression.  

Adolescent Period:  4 months through 6 months  During this stage, puppies begin to show breed specific characteristics such as herding, hunting, prey drive etc.  As these characteristics begin manifesting in your dog’s personality and temperament, your pup continues to form the foundation of his future responses and behaviors. For this reason, continued socialization is key during these weeks. Your interactions with your pup at this stage will have a huge impact on his behavior as he grows and matures. 

  • Provide exposure to a variety of different environments, people, dogs and other animals.   
  • Correct inappropriate responses to others (humans, dogs, children, and other animals).  Do not allow any behavior that will be unacceptable in an adult dog to become a habit for your puppy. 
  • Begin puppy socialization/training classes that focus on behavior and interaction with you rather than inter-puppy play. Your pup has already learned to play with other puppies in earlier stages of his development. Moving forward, focus on teaching him to look to you first for play, affection, and leadership.  

Beginning of Sexual Period: 6 months  Although I always caution against attributing human characteristics to dogs, this phase is biologically comparable to the beginning of puberty in humans. Raging hormones can cause behavioral changes. A previously inquisitive pup may suddenly show fear in strange surroundings.  Because these changes can make your pup feel confused and insecure, he needs your continued and consistent leadership. 

  • Continue controlled socialization. 
  • Continue training classes. 
  • Correct your dog for inappropriate responses and behaviors.  
  • Do not try to reassure or sympathize with your pup when he acts fearful or shows aggression. Your pup will interpret your reassurance as praise for being fearful or aggressive. 

Sexual Period/The Testing Phase:  7 months through 16 months.  As they reach sexual maturity, males begin to lift legs; females go into estrus. Those hormones are still raging.  Many pups go in and out fearfulness or demonstrate other changeable and uncharacteristic behavior without apparent reason. During this period, your puppy will begin to test you to see if you are worthy of the Alpha position, or leadership role.  He may disobey, be slow to comply with commands, show aggression, guard toys, food, or territory, or try to claim “Alpha” privileges, such as sitting on the furniture. Paradoxically, although pups at this stage challenge leadership, most don’t really want to be the leaders. Rather, they are seeking proof that they already have a strong leader in you. Although your pup may challenge you, he will feel safer and more secure when you remain consistent and firm. Your consistency will reassure him that you are still a strong and competent leader. 

  •   Continue training and correcting unacceptable behavior. 
  • Be alert for signs that your pup is preparing to challenge the dominance of another dog. Give your dog a command that prevents him from acting on his impulse before the situation escalates. 
  • Don’t allow him to get away with aggression with anyone or anything (i.e. other dogs, people).  Protecting the pack and its territory is the job of the Alpha. Allowing your pup to behave in territorial or confrontational ways sends the message that you are not on the job as leader.   
  • Correct any show of aggression and follow up with a command. The command indicates to your dog that you are in control of the situation and that he can depend on you to make the decisions.  


Although your puppy will undergo many changes in the first year of his life, most of his needs remain the same: food, safety, social interaction, an established role in a group, and leadership. What changes over time is how these needs are met. Initially, the pup’s needs are entirely met by his mother. However, when your puppy becomes part of your family, you must meet these needs. Understanding the stages of your puppy’s growth and development will help you meet his needs appropriately at each stage, thereby establishing a strong foundation for a well-adjusted and well-behaved adult dog.