| Typical puppy series start age | 6–8 weeks (American Animal Hospital Association (AAHA) Canine Vaccination Guidelines) |
| Typical kitten series start age | 6–8 weeks (American Association of Feline Practitioners (AAFP) Vaccination Guidelines) |
| Core puppy series completion | By 16 weeks of age (AAHA Canine Vaccination Guidelines) |
| Adult core vaccine cycle (post initial booster) | Every 3 years (most core vaccines) (AAHA and AAFP guidelines) |
| Rabies vaccination status | Required by law in most U.S. states (State and local public health regulations vary) |
| Bordetella booster frequency | Every 6–12 months for high-exposure dogs (AAHA Canine Vaccination Guidelines) |
Core Vaccines vs. Lifestyle Vaccines: What the Terms Mean
Every vaccine your vet recommends falls into one of two categories: core or non-core (sometimes called lifestyle vaccines). Understanding the difference helps you have a more informed conversation at your next visit.
Core vaccine
A vaccine recommended for all pets of a given species regardless of lifestyle, because the disease it prevents is widespread, severe, or transmissible to humans. Examples include rabies, distemper, and parvovirus for dogs.
Non-core (lifestyle) vaccine
A vaccine recommended selectively based on a pet's individual exposure risk — such as where they live, whether they go to boarding facilities, or whether they spend time outdoors. Bordetella and FeLV are common examples.
Maternal antibodies
Protective proteins passed from a mother to her offspring at birth or through nursing. They offer early immunity but fade within the first weeks of life, which is why a vaccine series rather than a single shot is used in puppies and kittens.
Titer test
A blood test that measures the concentration of antibodies against a specific disease, used to estimate whether a prior vaccine has produced lasting immunity. It does not replace legally required rabies vaccination.
Booster
A follow-up dose of a vaccine given after the initial series to maintain or renew protective immunity over time. Booster frequency varies by vaccine type and local regulations.
Core vaccines are recommended for virtually all dogs or cats, regardless of where they live or how much time they spend outdoors. For dogs, core vaccines typically include distemper, adenovirus (hepatitis), parvovirus, and rabies — often bundled as the DA2PP combination plus a separate rabies shot. For cats, the equivalents are feline herpesvirus, calicivirus, and panleukopenia (the FVRCP combo), plus rabies.
Non-core vaccines are recommended based on individual risk factors — your pet's environment, habits, and exposure to other animals. Examples include Bordetella (kennel cough) for dogs that visit groomers or dog parks, and feline leukemia virus (FeLV) for cats that go outdoors. Your vet is the right person to assess which of these apply to your pet. See our full breakdown of core and optional vaccines for a deeper look at how these decisions are typically made.
Puppy and Kitten Schedules: Why the Timing Matters
Young animals receive a series of vaccines rather than a single shot, and the spacing is deliberate. Puppies and kittens are born with some maternal antibodies — protective proteins passed from their mother — but these fade over the first weeks of life. The challenge is that maternal antibodies can also temporarily block a vaccine from working. Veterinarians use a series spaced roughly 3–4 weeks apart to ensure at least one dose lands after maternal immunity has waned but before the window of vulnerability grows too wide.
| Typical puppy series start age | 6–8 weeks (American Animal Hospital Association (AAHA) Canine Vaccination Guidelines) |
| Typical kitten series start age | 6–8 weeks (American Association of Feline Practitioners (AAFP) Vaccination Guidelines) |
| Core puppy series completion | By 16 weeks of age (AAHA Canine Vaccination Guidelines) |
| Adult core vaccine cycle (post initial booster) | Every 3 years (most core vaccines) (AAHA and AAFP guidelines) |
| Rabies vaccination status | Required by law in most U.S. states (State and local public health regulations vary) |
| Bordetella booster frequency | Every 6–12 months for high-exposure dogs (AAHA Canine Vaccination Guidelines) |
A typical puppy schedule begins around 6–8 weeks of age and continues through 16 weeks, with a final puppy-series dose often given at 12–16 weeks for parvovirus and distemper. Kittens follow a similar pattern, generally starting at 6–8 weeks and finishing the initial series by 16 weeks. Rabies is typically given as a single dose, often at 12–16 weeks depending on local regulations — and in most U.S. states, rabies vaccination is required by law.
If you're bringing a new pet home, our first 30 days health checklist can help you track what needs to happen and when.
Adult Booster Timing and Titer Testing
Once a pet completes its initial series, boosters become less frequent. Most core vaccines shift to a 3-year cycle for adult dogs and cats after the first annual booster — though some, like Bordetella, may be recommended annually or even every 6 months for high-exposure dogs. Rabies boosters follow local law, which varies by state and sometimes by county.
A Note on Titer Testing
Titer testing can provide useful information about your pet's existing immunity, but it is not a universal replacement for routine vaccination. Results can vary by laboratory, and no titer threshold has been universally validated as a legal substitute for rabies vaccination. Discuss the pros and cons with your veterinarian before making any changes to your pet's vaccination schedule.
Titer testing is an option some pet owners discuss with their vets. A titer test measures the level of circulating antibodies in the blood to assess whether a pet still has protective immunity from a prior vaccine. It does not replace required rabies vaccination where mandated by law, but it can sometimes inform decisions about other core vaccines for pets with health conditions that make frequent vaccination a concern. Ask your veterinarian whether titer testing makes sense for your pet's specific situation.
Vaccination records matter practically, too — many boarding facilities, groomers, and doggy daycares require proof of current vaccines. Keeping a copy of your pet's records at home makes that process easier. Your vet's annual or biannual wellness exam is the natural checkpoint for reviewing the schedule. Learn what else a wellness visit covers beyond vaccinations — it's more comprehensive than many owners expect.
If you're a first-time owner building the full picture of your pet's preventive care, the health foundations primer for new pet owners is a practical starting point.
This article is for general informational purposes only and is not a substitute for personalized veterinary advice. Always consult a licensed veterinarian for guidance specific to your pet's health, history, and local regulations.