Puppy Vaccination Schedule Explained

Puppies usually get their first core vaccine at about 6 to 8 weeks old, then repeat doses every 2 to 4 weeks until they are 16 weeks old or older. Another core dose follows somewhere between about 6 months and 1 year, depending on which guideline your vet follows, and other vaccines are added according to where you live and how your dog spends their time.

The two main guidelines, from AAHA (the American Animal Hospital Association) and WSAVA (the World Small Animal Veterinary Association), mostly agree, but they differ on a few details. Your vet's plan is the one to follow. This page explains the usual pattern so appointments make sense.

Core and non-core vaccines

Core vaccines are the ones guidelines recommend for essentially every dog. Non-core vaccines depend on lifestyle, location and risk.

Core:

• Distemper, adenovirus and parvovirus, usually given together in one shot. The adenovirus part also protects against infectious canine hepatitis. AAHA and WSAVA both list these as core for every dog.
• Rabies. AAHA lists it as core, and it is required by law in many places. WSAVA calls it core wherever rabies is endemic or local rules require it.
• Leptospirosis. AAHA changed it from non-core to core in a 2024 update to its guidelines. WSAVA treats it as core only where the disease is endemic, so your vet will decide based on your area.

Non-core, depending on risk:

• Bordetella (one of the causes of kennel cough), often paired with parainfluenza
• Lyme disease
• Canine influenza
• Western diamondback rattlesnake toxoid, for dogs in areas with these snakes

Parainfluenza is often added to the combination shot, but WSAVA lists it as non-core, and AAHA groups it with Bordetella among the non-core vaccines. Ask your vet which of these suit your dog. A dog who visits boarding kennels, daycare or groomers has different exposure than one who lives quietly at home. See our guide to kennel cough if you are weighing the Bordetella shot.

Typical puppy vaccination timeline

Exact ages differ between clinics. A common pattern looks like this:

Think of this as a map, not a rule. Do not skip a visit because your puppy looks fine. The dose given at 16 weeks or later is the one that most puppies can respond to.

Why puppies need several doses

Puppies get protective antibodies from their mother, mostly through her first milk (colostrum) in the hours after birth. Those antibodies protect the puppy for a while, but they can also block a vaccine from working. They fade at different speeds. WSAVA says they have dropped far enough in most puppies by about 8 to 12 weeks, but some puppies cannot respond to a vaccine until 12 weeks or later.

Because nobody can tell exactly when a given puppy becomes able to respond, vets give a series of doses. The repeated shots are not extra boosters in the usual sense. They are a way of making sure at least one dose lands once the mother's antibodies have faded. This matters a great deal for parvovirus, a serious and sometimes deadly illness in young dogs, because AAHA notes that maternal antibodies against it can linger to 13 to 15 weeks or longer.

Protection also takes time to build. VCA says a reasonable level is usually reached 10 to 14 days after a shot, so a single early dose is not enough.

Boosters after the puppy series

The two guidelines handle the first booster a little differently. WSAVA advises another core dose at or shortly after 26 weeks (about 6 months), or a blood test from 20 weeks to confirm the puppy is protected. AAHA recommends a booster within 1 year of the last puppy dose.

After that, both agree that the distemper, adenovirus and parvovirus combination does not need to be given every year. AAHA recommends boosters every 3 years, and WSAVA says to revaccinate no more often than every 3 years. Leptospirosis, Bordetella, Lyme and canine influenza vaccines are given every year when a dog needs them. Rabies vaccines come in 1-year and 3-year versions, and local law often sets the interval.

Outings and socialization before the series is finished

Merck notes that socialization matters most between about 2 and 4 months of age, and WSAVA calls early socialization essential to healthy behavioral development. At the same time, puppies are most vulnerable before the series is done. Ask your vet how to balance the two.

WSAVA says socialization can begin before the vaccine course is finished, as long as it happens under controlled conditions. Until the course is complete, keep your puppy away from dogs whose vaccine status you do not know and from places that may be contaminated, such as busy dog parks. Contact with healthy puppies and fully vaccinated adult dogs is a safer option, if your vet agrees.

A puppy class that checks vaccine records can be a good fit. Merck notes that some classes accept vaccinated puppies from 8 weeks old, and WSAVA points to research showing a low risk of parvovirus from well-run early classes.

What to expect after a shot

Many puppies are a little less lively or less hungry for a day or two, and VCA says this usually settles within 24 to 48 hours. Some soreness or swelling where the shot was given is also common. A small lump can form after some vaccines. If it is painful or has not started to shrink after a few weeks, tell your vet.

Questions to ask at the first visit

A few questions make the series easier to follow:

• Which vaccines does my puppy need where we live, and which can wait?
• When are the next doses, and when is the last puppy dose due?
• Is rabies required here, and at what age?
• When is it safe for my puppy to meet other dogs and visit public places?
• Can I get a written record of every vaccine, with dates and batch details?

Keep that record somewhere safe. Boarding kennels, groomers and trainers often ask for proof.

When to call your vet

Call your vet or an emergency clinic immediately if your puppy shows signs of a serious reaction after a shot, such as vomiting, diarrhea, difficulty breathing, facial swelling or hives. WSAVA notes that severe allergic reactions usually start within an hour of the injection. Also call if:

• Tiredness or low appetite lasts longer than a couple of days after a shot
• A vaccinated dog develops an illness that the vaccine was meant to prevent
• You have lost your puppy's records or are unsure which shots are due

Bring any paperwork from the breeder or shelter to your first visit, and our puppy first week checklist can help you plan for it.

Frequently asked questions

At what age can a puppy get its first vaccines?

AAHA and WSAVA both put the first core vaccine at about 6 to 8 weeks of age, with repeat doses every 2 to 4 weeks until your puppy is 16 weeks old or older. Your vet will set the exact dates.

Why does my puppy need so many shots?

Antibodies from the mother can block a vaccine from working, and nobody can predict exactly when they fade in an individual puppy. Giving several doses makes sure at least one lands when the puppy can respond.

Is the rabies vaccine part of the puppy series?

Rabies is usually a separate shot given from about 12 weeks of age, often between 12 and 16 weeks, with a booster about a year later. After that, the interval depends on the vaccine and on local law, so your vet will tell you what applies where you live.

Can I take my puppy to the park before they are fully vaccinated?

Ask your vet first. Until the full course is done, keep your puppy away from dogs whose vaccine history you do not know and from places where many dogs gather. Controlled contact with healthy puppies and fully vaccinated adult dogs is a safer way to socialize.

Written from veterinary sources by the Pawsplained editorial team. Not yet reviewed by a veterinarian; this is general information, not a diagnosis or treatment plan. Updated Oct 30, 2026. Editorial policy

Sources

1. AAHA: Recommendations for core and noncore canine vaccines
2. AAHA NEWStat: Leptospirosis vaccination recommended to be core for most dogs
3. WSAVA: 2024 Vaccination Guidelines
4. VCA Animal Hospitals: Vaccines for Dogs
5. Merck Veterinary Manual: Puppy Care