Puppy kindergarten is an important space to allow your puppy to be exposed to other dogs and people. Often puppy classes will have a play time where the puppies are able to interact and actually learn from each other how to play without hurting or upsetting another puppy (usually this has to do with learning to play gently with their mouths). Puppy kindergarten is also a great time for puppies to be around other people, including men and sometimes children (depending on the makeup of the class and the trainer's policies). A great way to help your dog become more comfortable with strangers is to play "pass the puppy" - the puppies move around the room in a circular fashion, stopping with each human, who spends a few minutes petting and handling the pup. By the end of this little exercise, your puppy has met more people that he would probably meet in a week (or a month) at home!
Veterinarians specializing in behavior generally agree that puppies can start class at 7 to 8 weeks of age. They should have their first round of shots, a first deworming, and remain up-to-date on their vaccinations throughout the class. According to most behaviorists, the risk of euthanasia of a dog due to behavioral issues (caused by a lack of adequate socialization) greatly outweighs the risk of a puppy contacting an illness at a well-run puppy class. Classes are most safely held inside on surfaces that can be disinfected, and all puppies attending class should be vaccinated (first round) and disease and parasite free. (See ASPCA for more information). `
The American Veterinary Society of Animal Behavior (AVSAB) reports "the fact is that behavioral issues—not infectious diseases—are the number one cause of death for dogs under 3 years of age, according to the AVSAB. Veterinarians contribute to these behavioral issues when recommending pets be kept away from possible germs until their vaccine series is complete, the AVSAB stated."