Your new puppy does not have a fully competent (operational) immune system until it is over 16 weeks of age. We recommend that the puppy have at least 2 sets of vaccinations done 3 weeks apart, with the final set occurring after the puppy is 16 weeks old. Typically, the 8 week old puppy (which is the most common “adoption” age) will need vaccinations every 2–3 weeks to stimulate a fully protective immune response to the various serious diseases that can infect your puppy.
Your puppy is also very susceptible to various intestinal parasites (hookworms, roundworms, whipworms, coccidia, giardia) at the younger than 16 weeks ages. The
puppy typically requires several deworming treatments before it is no longer shedding the parasite eggs in its fecal material.
Your puppy is typically not physically developed enough to safely play and compete with older, more active/ physical dogs until it is usually 14–16 weeks or older. It also has not learned the necessary “manners” or discipline to interact with older dogs. Just because it is a “puppy” does not mean that other dogs will not dominate, growl or be aggressive towards it, especially if the puppy intrudes on a favorite play-toy, or nips a sensitive area. You do not want your puppy’s experience at the Dog Park to be a bad or frightening one.