Veterinary Science Question:

Some dogs do not become adequately immunized against certain preventable diseases (Parvo most notably) until 18 to 20 weeks of age. Therefore avoidance of locations where many dogs of unknown background congregate or have been seems to make sense. However puppies do need to to be socialized by being exposed to many sites, sounds, and experiences so we recommend taking them to less "canine intensive" sites and exposing them to known healthy, vaccinated dogs belonging to friends. Since some diseases and parasites are transmitted by exposure to feces, you need to control where your puppy puts his nose when on his walks.