Ms Nanci Creedon:

As for puppy farms and early socialisation with dogs, there are between five and 12 weeks to expose a dog to as many different animals and people and anything that is a social experience as possible. True socialisation has to occur between five and 12 weeks. After 12 weeks the dog has left its socialisation period. It can learn and can have lots of pleasant or negative experiences, but between five and 12 weeks, if that dog is not exposed correctly to people and other animals, it will not be able to bond with people or take to them as almost like the same species, more or less.