Dog vaccination schedule: core shots, boosters and timing

You just brought home a puppy, and the vet handed you a record card with a string of dates on it. Why so many shots? Which ones are required and which are optional? Does your dog need boosters every year for life? A clear dog vaccination schedule answers all of that and helps you protect your dog without giving one shot too many or one too few.

This guide explains which vaccines the international guidelines from WSAVA (the World Small Animal Veterinary Association) recommend, lays out a week-by-week puppy schedule, covers how often adult dogs need boosters, what US rabies laws mean for you and which side effects are normal. Your vet will tailor the plan to where you live and how your dog spends their days.

Why puppies need a series of shots

For the first weeks of life, puppies are protected by antibodies they absorb from their mother’s first milk (colostrum). That protection is temporary, and while it lasts it also cancels out the vaccine: if maternal antibodies are still high, the shot can’t trigger the puppy’s own immune response.

The catch is that nobody knows exactly when those antibodies fade. In some puppies they drop around 8 weeks; in others they keep interfering until 12 weeks or even past 16. That’s why puppies are vaccinated every 2–4 weeks until they’re at least 16 weeks old: it shrinks the window in which a puppy is unprotected between the maternal antibodies fading and the vaccine that finally works.

For the same reason, a puppy isn’t considered fully protected until the series is complete, even after two rounds.

Core vs. non-core dog vaccines

WSAVA guidelines split vaccines into two groups:

• Core vaccines are for every dog, everywhere, because they protect against severe, widespread and often fatal diseases: distemper, canine adenovirus (infectious hepatitis) and parvovirus. Rabies counts as core wherever it’s required by law or the disease is present, which includes the US.
• Non-core or lifestyle vaccines depend on each dog’s risk: where you live, whether your dog boards, goes to daycare or the dog park, hikes, swims or travels.

Parvo is especially dangerous for puppies; our guide to parvovirus in dogs covers the symptoms and treatment. Kennel cough is usually mild, but most boarding facilities require the vaccine. And if you live in the Northeast, the upper Midwest or another Lyme hotspot, the vaccine works best alongside year-round prevention of ticks on dogs.

Puppy vaccination schedule, week by week

In the US, the core shots usually come as a combination vaccine called DHPP (also written DAPP or DA2PP): distemper, adenovirus, parvovirus and parainfluenza. This is a typical schedule based on WSAVA recommendations and common US practice. The first round often lines up with your puppy’s first vet visit, which also includes a full checkup and a deworming plan.

Adult dog boosters: does your dog need shots every year?

Not every vaccine lasts the same amount of time, so they don’t all need the same schedule:

• Core vaccines (DHPP): after the 6–12-month booster, WSAVA and AAHA recommend revaccinating no more often than every 3 years, because immunity from these vaccines lasts for years.
• Rabies: every 1 or 3 years, depending on the vaccine used and your state and local laws.
• Leptospirosis: yearly, since protection lasts about a year.
• Bordetella: yearly in most cases; some boarding facilities ask for it every 6 months.
• Canine influenza and Lyme: yearly, for dogs at risk.

For the core vaccines, there’s also the option of a titer test: a blood test that checks whether your dog still has protective antibodies against distemper, adenovirus and parvovirus. WSAVA considers it a valid way to decide whether to revaccinate, but it doesn’t work for leptospirosis and doesn’t replace a rabies vaccine required by law.

Age alone isn’t a reason to stop vaccinating, since senior dogs can still catch these diseases. Your vet will decide which vaccines to keep based on your dog’s health and lifestyle. If you adopt an adult dog with no known history, one or two doses of the core vaccines (depending on the product) plus any lifestyle vaccines they need are usually enough.

Rabies vaccination laws in the US

Rabies vaccination is required by law in most US states, and many counties and cities have their own rules on top of that. Laws typically set the age for the first shot (often between 12 and 16 weeks), how often boosters are due and whether your dog must wear a rabies tag or be licensed. Your vet or local animal control office can tell you exactly what applies where you live.

Staying current matters beyond the law. If an unvaccinated dog bites someone or is exposed to a rabid animal, such as a bat, raccoon, skunk or fox, the consequences can include a long, strict quarantine or even euthanasia, depending on local regulations.

International travel adds its own rules. Many countries require a microchip implanted before the rabies shot, a waiting period after vaccination and sometimes a rabies titer test months in advance. Check the USDA APHIS pet travel requirements for your destination early, and see our guide to flying with a dog.

Dog vaccine side effects

Most dogs have no reaction at all, or only mild effects that pass within 24–48 hours:

• Soreness at the injection site.
• Tiredness and extra napping.
• A low-grade fever and a smaller appetite.
• A small lump where the shot was given that fades over a few weeks.
• Sneezing or a mild runny nose for a few days after an intranasal vaccine.

Serious reactions are uncommon. If your dog has reacted before, tell your vet ahead of the next appointment: they may switch products, space out the vaccines or keep your dog for observation afterward.

Vaccines and your puppy’s first outings

Keeping a puppy home until every shot is done has a real cost: those first weeks overlap with the socialization period, when puppies learn to accept people, noises, surfaces and other dogs. The American Veterinary Society of Animal Behavior (AVSAB) advises against isolating puppies: they can start well-run puppy classes once they’ve had at least one round of vaccines a week beforehand and their first deworming.

The key is managing risk: carry your puppy in public places, skip busy dog parks and areas with dog poop, and set up playdates with healthy, vaccinated adult dogs. We cover it step by step in when puppies can go outside.

Frequently asked questions

What happens if my dog is late for a vaccine?

For an adult dog, being a few weeks late usually isn’t a problem: just get the shot as soon as you can. If a lot of time has passed, some vaccines, such as leptospirosis, need the two-dose starter series repeated. With rabies, a lapse can have legal consequences, so check your local rules. For puppies, the series has to finish at 16 weeks or later, and your vet will decide whether to continue or add a dose.

Do adult dogs really need vaccines every year?

Not all of them. After the first-year booster, core vaccines can be given every three years, according to WSAVA and AAHA, while leptospirosis, Bordetella, canine influenza and Lyme are given yearly to dogs at risk. Rabies depends on the vaccine and your local law. Keep the annual wellness exam either way, even in years when few shots are due.

Can a sick dog be vaccinated?

Usually not. If your dog is sick, has a fever or is very run-down, your vet will typically postpone the vaccine until they recover, because the immune response will be weaker and it’s harder to tell a reaction from the illness itself. Pregnant dogs also need a specific assessment, since some vaccines shouldn’t be given during pregnancy.

Is the Bordetella vaccine required?

It isn’t required by law, but most boarding kennels, daycares, groomers and training facilities require it. It comes as an intranasal, oral or injectable vaccine, and some products take longer than others to protect, so ask your vet how far ahead of a boarding stay your dog should get it. It reduces the risk and severity of kennel cough but doesn’t prevent every case.

Why is my puppy tired after shots?

Vaccines activate the immune system, so it’s normal for a puppy to sleep more, play less or eat a little less for a day or two. Let them rest, skip intense exercise that day and keep an eye on the injection site. If the lethargy is severe, lasts more than 48 hours, or vomiting or swelling appears, call your vet.

Sources

• WSAVA (World Small Animal Veterinary Association), Vaccination Guidelines Group: guidelines for the vaccination of dogs and cats.
• American Animal Hospital Association (AAHA): canine vaccination guidelines.
• Centers for Disease Control and Prevention (CDC): rabies information for pet owners.
• American Veterinary Society of Animal Behavior (AVSAB): position statement on puppy socialization.