Pet Vaccination Schedule Calculator

Core puppy and kitten shots run until at least 16 weeks, with a booster after 26 weeks

A puppy or kitten gets its first core vaccine at 6 to 8 weeks of age, then another dose every 2 to 4 weeks until it is at least 16 weeks old. After that comes a booster at or after 26 weeks, a revaccination at 3 years of age, and then no more often than every 3 years. That is the schedule in the 2024 guidelines of the World Small Animal Veterinary Association (WSAVA). For a puppy born on January 1, 2026 that starts at 8 weeks with doses 4 weeks apart, the three doses fall on Feb 26 (Thu), Mar 26 (Thu) and Apr 23 (Thu). The 26-week booster is Jul 2 (Thu), and the 3-year revaccination is Jan 1, 2029 (Mon).

Enter the date of birth plus the starting age and interval your vet uses, and the calculator works out how many doses you need and when. Each time a dose is given, record the date on its card and the next dose is counted from the day it was actually given, not the day it was planned. Rabies is shown with a first dose at 3 months of age or older and a booster 1 year later. You can add leptospirosis (dogs) and feline leukemia, FeLV (cats), with a switch.

Why a puppy or kitten needs several doses

Newborn puppies and kittens get antibodies from their mother through her first milk. These maternal antibodies protect the young animal, but while they last they can also stop a vaccine from working. WSAVA explains that in most puppies and kittens maternal antibodies fall low enough for a vaccine to work by about 8 to 12 weeks of age. A pup with a lot of maternal antibody may not respond until after 12 weeks, and one with little can become vulnerable much earlier.

The stretch when maternal antibodies are too low to prevent disease but still high enough to block the vaccine is called the window of susceptibility. Nobody can tell in advance when it opens and closes for a given animal. So doses are repeated every 2 to 4 weeks to narrow the window, and the last dose of the series is given at 16 weeks or older so that most animals respond. A shorter interval narrows the window more, but it means more visits. On the calculator's age map, the fading band shows the period when maternal antibodies are declining.

• A new puppy or kitten: record the doses and dates from the breeder or shelter on the cards, and the remaining doses and next date appear right away.
• Vets that use different intervals: compare how 2, 3 and 4 weeks apart change the number of doses and the date the series ends.
• Planning walks, grooming or boarding: use the full-immunity date, 2 weeks after the last dose of the series, as your reference.
• Sharing the plan with family: share the link or the calendar file so nobody misses the next vet visit.

How the dates are calculated

1. First dose: the date of birth plus the starting age (6 to 10 weeks) times 7 days. If the dose was already given, the recorded date is used.
2. Next dose: the date the previous dose was actually given plus the interval (2, 3 or 4 weeks) times 7 days.
3. End of the series: the dose given at 16 weeks (112 days) or older is the last one. That is why the number of doses ranges from 3 to 6 depending on the starting age and interval.
4. First dose after 16 weeks: 2 doses at the chosen interval, then a booster within 1 year (AAHA).
5. 26-week booster: the later of 26 weeks of age (182 days) and 4 weeks after the last dose of the series. WSAVA also allows an antibody test at least 4 weeks after the last dose (at 20 weeks or older) in place of this booster.
6. Revaccination: on the 3rd birthday (date of birth plus 36 months), then every 3 years. If that month has no matching day, the last day of the month is used.
7. Full immunity (approx.): the date of the last dose of the series plus 14 days. WSAVA notes that a full immune response may not develop until 2 weeks after the final dose.
8. Rabies: the first dose at 3 months after birth, the second 1 year after the first, then every 1 year or every 3 years depending on the vaccine (the 3-year date is shown for a 3-year vaccine).
9. Leptospirosis and FeLV: dose 1 at 8 weeks, dose 2 after the interval (3 to 4 weeks for FeLV), then once a year.
10. An overdue dose: the first dose not yet given is treated as given today, and the dates after it follow from that. Days left are counted by date only.

Sources The WSAVA 2024 guidelines and tables, the AAHA 2022 canine guidelines, the AAHA/AAFP 2020 feline guidelines and the NASPHV rabies Compendium were checked against the original documents on 2026-10-23.

The starting age and interval give 3 to 6 doses

These dates are for a puppy born on January 1, 2026. Doses continue until the last one falls at 16 weeks or older, so a shorter interval or an earlier start means more doses.

In every case the 26-week booster is Jul 2, 2026 (Thu) and the 3-year revaccination is Jan 1, 2029 (Mon). Your vet chooses the interval. The WSAVA table lists 3 to 4 weeks as the standard and also describes continuing every 2 to 3 weeks up to 20 weeks of age when the risk of infection is especially high.

WSAVA and AAHA agree on the series and differ on the first booster

The three main guidelines for dogs and cats in the United States and worldwide use the same basic series: start at 6 to 8 weeks and continue until at least 16 weeks. They differ mainly on when the first booster is given and how far the series should extend.

This calculator follows WSAVA for the 26-week booster and the 3-year revaccination, and it follows AAHA for a first dose given after 16 weeks. Both guidelines say annual boosters of the core vaccines are not necessary once the series and first booster are done. Leptospirosis is the exception for dogs: it is repeated every year. Whether to use an antibody test instead of a booster, and which optional vaccines your pet needs, depends on where you live and the product used, so decide with your vet.

Rabies: 3 months or older, then follow your state and the product label

Rabies vaccines licensed in the United States are labeled for animals 3 months of age and older (AAHA). The Compendium of Animal Rabies Prevention and Control from the National Association of State Public Health Veterinarians (NASPHV, 2016) says that, regardless of the animal's age at the first vaccination, a booster should be given 1 year later. After that, the interval follows the vaccine's label, either 1 year or 3 years. The calculator shows both: a yearly date, and the date that applies if your vet uses a 3-year vaccine.

The Compendium states that its recommendations do not supersede state and local laws or requirements. Rabies rules differ by state, county and city: some set the age at first vaccination, how long a vaccine counts, or whether a tag or license is required. Check the rules for where you live with your vet or your local animal control or health department. WSAVA also says to follow local law first.

Starting late or missing records

• A dog whose first dose comes after 16 weeks: AAHA recommends 2 doses 2 to 4 weeks apart and a booster within 1 year. WSAVA says that for a dog over 26 weeks a single dose of a modified live (MLV) core vaccine is very likely enough, and suggests a second dose 2 to 4 weeks later in high-risk situations.
• An adult cat: one dose of an MLV panleukopenia vaccine is enough for most cats, but the herpesvirus and calicivirus vaccines are less potent. WSAVA supports two doses 2 to 4 weeks apart, as manufacturers recommend.
• Doses that ran late during the series: give the remaining doses as soon as possible, and the next dose is counted from the day it was actually given. If the delay was long, your vet will set a catch-up plan.
• If you can find records: bring the vaccine record or earlier vet records with the dates and product names. Dates calculated only from the birth date are not your pet's current vaccine plan.

Leptospirosis, FeLV and other optional vaccines

WSAVA sorts vaccines into core vaccines that every animal should get, non-core vaccines chosen by location and lifestyle, and vaccines it does not recommend because the evidence is weak.

AAHA lists leptospirosis for dogs as two doses 2 to 4 weeks apart starting at 12 weeks, a booster within 1 year, then yearly. The calculator uses the earlier WSAVA start at 8 weeks.

Common mistakes

• Treating a past date as a given dose: a past date on the calculator is only a planned date. It counts as given only when you record it on the card.
• Finishing the series before 16 weeks: if the series ends at 14 weeks, as with 8, 11 and 14 weeks, a puppy with maternal antibodies that last longer may not be protected.
• Counting the next dose from the planned date: if a dose slipped, count the interval from the day it was actually given.
• Missing the rabies booster: give the second rabies dose 1 year after the first, whatever the age at the first dose.
• Giving FeLV without a test: the FeLV vaccine is for cats that tested negative.
• Counting 3 months as 12 weeks: the calculator counts the rabies "3 months" as calendar months. For a pet born on January 1 that is April 1 (Wed), six days after the 12-week date of March 26 (Thu).

Limits and cautions

• This is a reference schedule based on international and US guidelines. Your vet decides the actual vaccines and dates from your pet's health and the product instructions.
• The schedule differs for animals that are pregnant, ill, on medication, or living in a shelter, kennel or other high-risk place.
• Rabies law differs by state and locality, and the calculator does not know yours. Check it before relying on any rabies date.
• Your entries are stored only in this page's address (the link) and are not saved on the site. Copy the link or save the calendar file to keep them.

Sources

• 01Squires RA et al.: 2024 guidelines for the vaccination of dogs and cats (WSAVA VGG), J Small Anim Pract 65(5):277–316Start at 6 to 8 weeks, every 2 to 4 weeks, 16 weeks or older; maternal antibodies at 8 to 12 weeks; booster at 26 weeks or an antibody test; immunity 2 weeks after the last dose; adult dogs and cats; canine coronavirus vaccine not recommended
• 02WSAVA: Dogs Vaccination Table (PDF)Revaccinate at 3 years, then no more often than every 3 years; leptospirosis from 8 weeks, yearly; rabies per local law
• 03WSAVA: Cats Vaccination Table (PDF)Low-risk cats every 3 years from 3 years of age, higher-risk cats up to yearly; FeLV from 8 weeks, 3 to 4 weeks apart, a dose at 1 year, test negative only
• 04AAHA: 2022 Canine Vaccination GuidelinesSeries past 16 weeks; booster within 1 year, then every 3 years; 2 doses if the first is after 16 weeks; leptospirosis from 12 weeks; rabies labeled for 3 months and older
• 05Stone AE et al.: 2020 AAHA/AAFP Feline Vaccination Guidelines, J Feline Med Surg 22(9):813–830Series every 3 to 4 weeks to 16 to 20 weeks; booster at 6 months, then every 3 years; FeLV for kittens under 1 year, test first
• 06NASPHV: Compendium of Animal Rabies Prevention and Control, 2016, J Am Vet Med Assoc 248(5):505–517Booster 1 year after the first dose regardless of age, then per the product label; does not supersede state and local laws

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