Puppy development follows an expected timeline, with some individual and/or breed differences.
All caretakers should understand the stages of development of a puppy’s first year. This helps caretakers:
- avoid negative experiences for their puppy
- provide puppies with opportunities to learn positive associations
- reduce unwanted behavior in adult dogs
- recognize and intervene when problems arise
SENSITIVE PERIOD FOR SOCIALIZATION
Puppies enter the sensitive period for socialization at approximately three weeks of age. Their hearing and vision are developed, and now puppies are ready to explore. They are also comfortable approaching new people and objects. At around week five, they are most likely to show approach behaviors.
During this time, puppies need many brief and positive interactions with people. Isolation from other dogs and negative experiences as puppies can cause unwanted behaviors later. The sensitive period lasts until 12-16 weeks of age. This is when dogs become more fearful and less exploratory.
During the socialization period, puppies also experience a fear stage. The fear stage starts at approximately eight weeks of age, but breeds and individuals may differ. The best way to know when a puppy enters the fear stage is to observe their behavior. Puppies will be reluctant to approach new people or objects. At around 8-9 weeks of age, traumatic experiences can be especially harmful to puppies.
The development of fear behavior in puppies can vary by dog breed, and there can be individual differences.
Morrow, M., Ottobre, J., Ottobre, A., Neville, P., St-Pierre, N., Dreschel, N. and Pate, J.L. (2015). Breed-dependent differences in the onset of fear-related avoidance behavior in puppies. Journal of Veterinary Behavior: Clinical Applications and Research, 10, 286- 294.
Developmental Stages Library
Bare Bones – If you only have a few minutes for the basics
SNACKS – If you want to learn More
Implications of Weaning Age for Dog Welfare - CRONEY RESEARCH GROUP
Your Puppy's Development
Fear, Stress, and Puppy Brain Development: What to Know
Early Experience and the Development of Behavior
Dog Behavior: Modern Science and Our Canine Companions
Genetics and the Social Behavior of the Dog
Dog Behaviour, Evolution, and Cognition 2nd Edition
Early Rearing Environment
Kibble – If you want to take a deep dive into the SCIENce
The Effect of Transportation on Puppy Welfare From Commercial Breeding Kennels to a Distributor - CRONEY RESEARCH GROUP
Critical Periods in the Development of Social Behavior in Puppies
Breed-Dependent Differences in the Onset of Fear-Related Avoidance Behavior in Puppies
Teenage Dogs? Evidence for Adolescent-Phase Conflict Behaviour and an Association Between Attachment to Humans and Pubertal Timing in the Domestic Dog
Additional Resources to Support Dogs in Other Environments
SHELTER & RESCUE
Dogs living in shelter or rescue kennels face challenges specific to their living environments. Practical applications for their management and care may also differ. Additional resources for their caretakers, including those caring for dogs in home-based foster systems or rescue networks, are provided to support efforts to improve, maintain, and protect their welfare.
Dogs living in homes as family pets face challenges specific to their living environments. Practical applications for their management and care may also differ. Additional resources for their caretakers, support the human-animal bond, keep pets in their homes, and improve, maintain, and protect their welfare.
Research & Teaching
Dogs living in research or teaching kennels face challenges specific to their living environments. Practical applications for their management and care may also differ. Additional resources for their caretakers are provided to support efforts to improve, maintain, and protect their welfare.
Applications for Research & Teaching
Applications for Pet Families
Dog Pregnancy: Signs, Care, and Preparing for Puppies
Meyers, H. (2022, April 21). Dog pregnancy: Signs, care, and preparing for puppies. American Kennel Club. Retrieved June 23, 2022, from https://www.akc.org/expert-advice/dog-breeding/dog-pregnancy-care-prep/
Dog Behavior: How the Past Shapes the Present
Star of Texas Veterinary Hospital. (2021). Dog Behavior: How the Past Shapes the Present. Retrieved June 20, 2023, from https://staroftexasvet.com/dog-behavior-how-the-past-shapes-the-present/.