Puppy Vaccination Schedule

Most puppies have their first shots at 6 to 8 weeks, then visit the vet every 3 to 4 weeks until about 16 weeks old. A booster visit follows about a year later. Here is the typical plan, based on the American Animal Hospital Association (AAHA) Canine Vaccination Guidelines:

Core vaccines are recommended for every dog, because the diseases are serious, widespread, or can spread to people:

• DHPP combination: distemper, adenovirus (canine hepatitis), parvovirus, and usually parainfluenza. Parvovirus in particular is common and often deadly in unvaccinated puppies.
• Rabies: required by law in most of the US, with timing set by state or local rules.
• Leptospirosis: a bacterial infection spread through water and wildlife urine, which can also infect people. AAHA moved it to the core list in 2024.

Lifestyle vaccines depend on where your dog goes. Bordetella (kennel cough) and canine influenza are usually needed for dogs who go to daycare, boarding, grooming, training classes, or dog parks. The Lyme disease vaccine is for dogs in areas with ticks that carry Lyme. Your vet will help you decide.

Puppies get some protection from their mother's milk, but those antibodies fade at an unpredictable time between about 6 and 16 weeks. While they are still around, they can block a vaccine from working. Giving the vaccine every few weeks until about 16 weeks makes sure one dose “takes” as soon as the mother's protection wears off. That is why the last puppy dose matters so much, even if the earlier ones went smoothly.

The weeks before 16 weeks old are also the most important time for socialization, so waiting until every shot is done can backfire. Veterinary behaviorists recommend:

• Puppy classes that check vaccine records, starting about a week after the first vaccines.
• Playdates with healthy, fully vaccinated dogs you know.
• Carrying your puppy to see new sights and sounds, without letting them sniff where unknown dogs go.
• Skipping dog parks and busy dog areas until your vet says the vaccine series is complete.

• Deworming: puppies are commonly dewormed several times in their first months.
• Heartworm prevention: the American Heartworm Society recommends starting by 8 weeks old.
• Flea and tick prevention: ask your vet which products are safe for your puppy's age and weight.
• Microchip: often done at a puppy visit, and the best way to get a lost dog home.
• Spay or neuter: the best timing depends on breed and size, so talk it through with your vet.

Curious how big your puppy will get, or how old they are in human years? Try our dog age calculator.