Young puppies are highly susceptible to certain infectious diseases and should be vaccinated against them as soon as they are old enough to build immunity. These diseases are distemper, infectious hepatitis, parvovirus, parainfluenza, and rabies. Leptospirosis, giardia, coronavirus, bordetella, bronchiseptica, and Lyme disease vaccinations are optional, depending on the occurrence of these diseases in your area and your dog’s individual risk factors.
The American Animal Hospital Association (AAHA) has drawn up guidelines categorizing vaccines as core, noncore, or not recommended, and these categories will be indicated for all the vaccines described in this section. While these guidelines suggest that puppies as young as 6 weeks may be vaccinated, most veterinarians and breeders wait until 7 or 8 weeks of age. Also, vaccine recommendations state that many vaccines do not need boosters beyond 12 weeks of age, but veterinarians, particularly in endemic disease areas, may do a final puppy vaccine at about 16 weeks.