Puppy Development and Fear Stages by Dr. Megan Bauer


Puppies go through a socialization phase from about 3 to 14 weeks of age. During this time, they will react to most novel experiences with curiosity. Making sure that they have lots of exposure to sights, smells, sounds, surfaces, people, and other animals during this critical time will help set your puppy up for success at not being fearful later in life. It is crucial that their socialization experiences be positive – exposure does not necessarily equal socialization and one bad experience can outweigh a hundred good experiences. Experiences that scare your puppy may cause phobias before the fear period even begins.


By the age of 6 months old, your puppy will have already gone through about 2 fear periods since you brought them home (breed dependent). You may notice that your previously confident, curious puppy is now showing hesitancy to approach new objects or people, barking, comfort-seeking, or hiding/retreating. These behaviors are more pronounced in puppies that are genetically cautious or fearful and puppies who were under-socialized, but even puppies who are happy-go-lucky will go through this stage as a normal part of development.


To help your puppy through their fear period, continue socializing your puppy and allowing them to have positive experiences, while supporting them if they seem cautious or fearful. Your puppy may need additional patience from you during this time. Never punish your puppy for showing signs of fear, as this can compound their fear and may cause them to become aggressive.


Your puppy will enter another fear period sometime during adolescence depending on breed, size, and genetics. This fear period is usually more pronounced and may last longer than the first fear period. Like the first fear period, we want to support our puppies so that they continue to have positive experiences and help prevent them from making negative core memories. During this period, additional training and desensitization may be necessary.


Although all puppies go through this period as a normal part of development, phobias and fear-based aggression are not to be expected. If you notice severe signs of fear, please contact your veterinarian or a positive-reinforcement dog trainer for help as this may be a sign of a more serious underlying issue.