Puppy vaccine schedule: AAHA core shots and timing
The question
Which shots does my puppy need, and when?
Short answer
Under the 2022 AAHA canine vaccination guidelines, updated in 2024, every dog should get the core vaccines: distemper, adenovirus, parvovirus, leptospirosis and rabies. Puppies get a combination shot every 2–4 weeks from 6–8 weeks until they are older than 16 weeks, two leptospirosis shots from 12 weeks, rabies as the law where you live requires, and a booster within a year. Your vet sets the exact plan.
Updated · sources read · Data and sources →
The American Animal Hospital Association (AAHA) publishes canine vaccination guidelines for veterinary teams. The current version was published in 2022 and updated in 2024, and the update made one notable change: leptospirosis is now a core vaccine for all dogs.
This guide explains what the guidelines say and why the timing works the way it does. It is not a schedule for your puppy. AAHA itself calls its document a guideline, not a standard of care, and your vet will adjust it for your puppy’s age, health, history and where you live.
Core and noncore vaccines
AAHA sorts dog vaccines into two groups.
Core vaccines are recommended for every dog, whatever its lifestyle, unless there is a medical reason not to vaccinate:
- canine distemper virus;
- canine adenovirus type 2;
- canine parvovirus type 2;
- leptospirosis, core since the 2024 update;
- rabies.
The first three usually come together in one combination shot, sometimes with parainfluenza added.
Noncore vaccines are for some dogs, based on lifestyle, location and risk of exposure: Bordetella, Lyme disease, canine influenza, and a rattlesnake vaccine. Whether your puppy needs any of these is a question about where it will live, travel, board and play, and your vet is the one to answer it.
The puppy series: why so many shots
A puppy gets antibodies from its mother, and while they last they can block a vaccine from working. AAHA’s parvovirus chapter says these maternal antibodies fade over time and may last 13–15 weeks or longer, so a single early shot may not take.
The answer is a series. For the distemper-adenovirus-parvovirus combination, AAHA recommends:
- starting at 6–8 weeks of age;
- at least three shots, 2–4 weeks apart;
- continuing until the puppy is older than 16 weeks, with 18–20 weeks preferred where parvovirus risk is high.
That last rule decides how many shots a puppy gets. A puppy started at 8 weeks on a 3-week spacing gets shots at 8, 11, 14 and 17 weeks. On a 4-week spacing it gets 8, 12, 16 and 20 weeks: the 16-week shot isn’t after 16 weeks, so a fourth follows. Both are illustrations of the rule, not a plan for your puppy.
A dog first vaccinated when it is already older than 16 weeks needs two combination shots, 2–4 weeks apart.
Leptospirosis
Leptospirosis is a bacterial disease, and AAHA says all dogs in North America should be considered at risk. It is no longer mainly a disease of large rural dogs: AAHA notes small-breed dogs are frequently infected, perhaps through contact with rodents and other wildlife in cities and suburbs.
The puppy plan is two shots, 2–4 weeks apart, starting at 12 weeks of age. AAHA suggests not giving the first one earlier, because reactions are more likely in smaller and younger dogs, though it describes reactions to leptospirosis vaccines as rare, under 53 per 10,000 doses. Because the protection lasts 12 to 18 months depending on the strain, leptospirosis needs a booster every year.
Rabies
Rabies is the one vaccine where the law, not only the guideline, sets the rules. AAHA’s table simply says “as required by law.” The rules for when the first shot is due and how often boosters are given are set by your state and local government and vary across the country. Ask your vet or your local animal-control office.
What AAHA does say: all licensed rabies vaccines for dogs are labeled for puppies 3 months of age and older, and a booster is recommended one year after the first shot, whichever product was used. After that, products with one- and three-year intervals exist, and the law where you live decides which applies. A blood antibody test is not a substitute for the vaccine.
After the puppy series
| When | Core vaccine plan in the AAHA guidelines |
|---|---|
| 6–8 weeks to older than 16 weeks | Combination shots every 2–4 weeks |
| From 12 weeks | Two leptospirosis shots, 2–4 weeks apart |
| From 3 months, as the law requires | Rabies |
| Within 1 year of the last puppy shot | One combination booster and one leptospirosis booster |
| Every 3 years after that | Combination booster |
| Every year | Leptospirosis booster |
AAHA’s distemper chapter is direct that annual combination boosters are not necessary once a dog has had its puppy series and its first booster. For the 8-11-14-17-week puppy above, the first booster falls due by 69 weeks of age, about 16 months.
Missed a shot, or adopted a dog with no records? AAHA says the benefits of vaccinating outweigh the risks for dogs with an unknown history, points vets to the manufacturer’s instructions for overdue vaccines, and sums it up as a rule of thumb: when in doubt, vaccinate. Bring any paperwork you have to the first visit.
What the shots cost
ASPCA’s 2021 example budget for a dog puts initial medical costs, including vaccines, at $300 in the first year and routine medical care, including vaccines and wellness visits, at $225 a year after. Those figures are not adjusted for inflation, and your own vet’s prices may differ. The cost of owning a dog guide has the full budget and how vet prices have moved since.
This is general information, not veterinary advice — your vet decides your puppy’s vaccine plan.
Next step
Take your puppy’s records to each visit and ask your vet to write down the dates of the remaining shots and the first booster. Those visits are also a good time to weigh your puppy; you can follow its growth with the puppy weight calculator and the puppy growth chart.
Calculators for this guide
- Puppy weight calculatorYour puppy’s likely adult weight from age, weight and breed or size, with the range half of puppies like yours end in.
- Puppy growth chart & weigh-in trackerUp to 12 weigh-ins on centile lines from open veterinary data, with the weekly gain and a flag when the curve crosses lines.
Sources
Each source was read on the date shown. When one changes, this guide and its date change with it.
- 2022 AAHA Canine Vaccination Guidelines (2024 update)
- 2022 AAHA Canine Vaccination Guidelines: recommendations for core and noncore canine vaccines (Table 2)
- 2022 AAHA Core and Noncore Vaccines for Dogs, Table 2 (updated), printable PDF
- 2022 AAHA Canine Vaccination Guidelines: canine parvovirus
- 2022 AAHA Canine Vaccination Guidelines: canine distemper virus
- 2022 AAHA Canine Vaccination Guidelines: leptospirosis
- 2022 AAHA Canine Vaccination Guidelines: rabies
- Cutting Pet Care Costs
Printed from Puppy Scale (puppyscale.com/guides/puppy-vaccine-schedule/) · updated October 7, 2026 · general information, not veterinary advice.