Puppies go thorough a critical period of socialization between eight and 16 weeks of age. (canismajor.com)
Though a dog's sensitive period of socialization typically ends around 4 - 5 months old, we recommend continuing to socialize your dog for at least the first year of their life. (animalhumanesociety.org)
The first six months of a dog's life include crucial periods of socialization, both with humans and other dogs. (discovermagazine.com)