| Puppy vaccine series starts | 6–8 weeks of age (AAHA Canine Vaccination Guidelines) |
| Kitten vaccine series starts | 6–8 weeks of age (AAFP Feline Vaccination Guidelines) |
| Rabies vaccine timing (dogs & cats) | 12–16 weeks (first dose) (Varies by state law) |
| Adult core booster interval (dogs) | Every 3 years (post-series) (AAHA Canine Vaccination Guidelines) |
| Adult core booster interval (cats) | Every 3 years (post-series) (AAFP Feline Vaccination Guidelines) |
| Bordetella booster frequency | Annually or every 6 months (risk-based) (Varies by product and exposure) |
Core vs. Non-Core Vaccines: Know the Difference
Vaccines for dogs and cats fall into two categories: core and non-core. Understanding this distinction helps you have more informed conversations with your veterinarian.
Core vaccine
A vaccine recommended for all pets of a species regardless of lifestyle, because the target disease is widespread, severe, or a public health risk.
Non-core vaccine
A vaccine recommended selectively based on an individual pet's risk factors, such as geographic location, environment, or behavioral exposure.
Booster
A follow-up dose of a vaccine given after the initial series to maintain or restore protective immunity over time.
Maternal antibodies
Protective proteins passed from a mother to her offspring through colostrum that provide temporary immunity but fade within weeks, creating the need for early vaccination.
FVRCP
A combination vaccine for cats covering feline viral rhinotracheitis (herpesvirus-1), calicivirus, and panleukopenia — all considered core vaccines.
Titer test
A blood test that measures a pet's existing antibody levels to a specific disease, sometimes used to help determine whether a booster vaccine is currently needed.
Core vaccines are recommended for virtually every pet regardless of lifestyle, because the diseases they prevent are either highly contagious, potentially fatal, or transmissible to humans. For dogs, core vaccines include rabies, canine distemper, canine parvovirus, and canine adenovirus (hepatitis). For cats, the core set covers rabies, feline panleukopenia (distemper), feline herpesvirus-1, and feline calicivirus — the latter two often combined in the FVRCP vaccine.
Non-core vaccines are recommended based on a pet's individual risk profile — their environment, lifestyle, geographic region, and exposure history. Examples include Bordetella (kennel cough) for dogs that board or visit dog parks, leptospirosis for dogs in areas with wildlife exposure, and feline leukemia virus (FeLV) for cats that go outdoors. Your vet is the right person to assess which non-core vaccines make sense for your specific pet. See what a routine wellness exam covers for how these decisions typically unfold during a checkup.
Puppy and Kitten Schedules: The First Year
Young animals receive maternal antibodies through colostrum (first milk), but this protection fades — leaving a window of vulnerability that vaccines are designed to close. Because the exact timing of maternal antibody decline varies by individual, vets use a series of early vaccines rather than a single shot.
| Puppy vaccine series starts | 6–8 weeks of age (AAHA Canine Vaccination Guidelines) |
| Kitten vaccine series starts | 6–8 weeks of age (AAFP Feline Vaccination Guidelines) |
| Rabies vaccine timing (dogs & cats) | 12–16 weeks (first dose) (Varies by state law) |
| Adult core booster interval (dogs) | Every 3 years (post-series) (AAHA Canine Vaccination Guidelines) |
| Adult core booster interval (cats) | Every 3 years (post-series) (AAFP Feline Vaccination Guidelines) |
| Bordetella booster frequency | Annually or every 6 months (risk-based) (Varies by product and exposure) |
For puppies, the standard schedule begins at 6–8 weeks of age with the first distemper-parvovirus combination. Boosters follow every 2–4 weeks until the puppy is at least 16 weeks old. Rabies vaccine is typically given at 12–16 weeks, depending on local regulations. A booster is given one year after the final puppy series dose.
For kittens, the FVRCP series usually starts at 6–8 weeks, with boosters every 3–4 weeks until 16 weeks. Rabies is administered at 12–16 weeks. FeLV vaccination is generally recommended for all kittens during their first year, with an adult booster based on lifestyle. This first-year framework is covered in more detail in your pet's first-year health roadmap.
Adult Booster Intervals and What They Mean
Once the initial series is complete, vaccines shift to a booster schedule. Not all vaccines require annual boosters — this is a common misconception worth addressing directly.
Booster Intervals Are Not Always Annual
A common assumption is that every vaccine requires a yearly booster — but current veterinary guidelines differentiate by vaccine type and the pet's age and risk level. For example, after the initial series and one-year booster, the DHPP (dogs) and FVRCP (cats) vaccines may be given every three years for healthy adult pets. Always confirm the appropriate schedule with your veterinarian rather than defaulting to annual for every vaccine.
Rabies boosters follow local legal requirements, which vary by state and municipality — your vet will know the rules for your area. The canine distemper-parvovirus combination and feline FVRCP vaccines are often given every 3 years in adult pets following a strong response to initial boosters, based on guidelines from the American Animal Hospital Association (AAHA) and the American Association of Feline Practitioners (AAFP).
Non-core vaccines like Bordetella and leptospirosis may require annual or even semi-annual boosters depending on ongoing exposure risk. The right interval is determined by the vaccine product, the pet's health status, and clinical judgment — not a one-size-fits-all calendar. Keeping vaccination records organized matters here: your vet can quickly identify what's due, and you'll need documentation if your pet boards, travels, or visits a groomer. This pairs well with year-round parasite prevention, which is often coordinated at the same wellness visits.
This article is for general informational purposes only and does not constitute veterinary advice. Consult a licensed veterinarian for guidance specific to your pet's health history and needs.