| Puppy series start age | 6–8 weeks (American Animal Hospital Association (AAHA) Canine Vaccination Guidelines) |
| Kitten series start age | 6–8 weeks (American Association of Feline Practitioners (AAFP) Vaccination Guidelines) |
| Puppy/kitten booster interval | Every 2–4 weeks until ~16 weeks old (AAHA and AAFP guidelines) |
| Rabies vaccine (dogs & cats) | First dose at 12–16 weeks; booster schedule set by local law (Varies by state/municipality and vaccine license) |
| Adult core vaccine frequency | Every 3 years for most core vaccines after initial series (AAHA Canine Vaccination Guidelines; AAFP Feline Vaccination Guidelines) |
| Kennel cough vaccine type | Non-core; recommended for dogs in boarding, daycare, or dog parks (AAHA guidelines) |
Core vs. Non-Core Vaccines: What the Terms Mean
When your veterinarian talks about your pet's vaccination plan, you'll often hear two categories: core and non-core vaccines. Understanding the difference helps you have more informed conversations at every checkup.
Core vaccine
A vaccine recommended for all pets of a given species because the disease it prevents is highly contagious, serious, or poses a public health risk. Core vaccines are considered essential regardless of a pet's individual lifestyle.
Non-core vaccine
A vaccine recommended selectively based on a pet's specific risk factors, such as geographic location, frequency of contact with other animals, or time spent outdoors. Your vet helps determine which non-core vaccines are appropriate.
Booster
A follow-up dose of a vaccine given after the initial shot (or series) to maintain or strengthen immune protection over time. Booster intervals vary by vaccine type and local regulations.
Maternal antibodies
Protective proteins passed from a mother to her offspring through colostrum (early milk). While beneficial at birth, these antibodies can temporarily block a young animal's response to vaccines, which is why puppy and kitten series require multiple doses.
DHPP
A combination vaccine for dogs that covers Distemper, Hepatitis (adenovirus), Parainfluenza, and Parvovirus in a single injection. It is a standard core vaccine in canine preventive care.
FVRCP
A combination vaccine for cats covering Feline Viral Rhinotracheitis (herpesvirus), Calicivirus, and Panleukopenia. It is considered a core vaccine for virtually all cats.
Core vaccines are recommended for virtually every dog or cat, regardless of lifestyle, because the diseases they prevent are either highly contagious, potentially fatal, or transmissible to people. For dogs, core vaccines typically include rabies, distemper, parvovirus, and adenovirus (commonly combined in a single DHPP shot). For cats, core vaccines generally cover rabies, feline herpesvirus, calicivirus, and panleukopenia (combined in an FVRCP shot).
Non-core vaccines are recommended based on a pet's individual risk profile — where they live, how often they interact with other animals, and their environment. Examples include Bordetella (kennel cough) for dogs who visit boarding facilities, and feline leukemia virus (FeLV) vaccine for cats who spend time outdoors. Your vet is the best person to assess which non-core vaccines make sense for your specific pet.
For a broader look at how vaccination fits into lifelong care, see the Pet Health & Vets hub for additional guidance.
Puppy and Kitten Vaccination Timelines
Young animals receive a series of vaccinations — not just one shot — because maternal antibodies passed through mother's milk can temporarily interfere with vaccine effectiveness. Spacing out doses gives the immune system a chance to build its own protection as those maternal antibodies fade.
| Puppy series start age | 6–8 weeks (American Animal Hospital Association (AAHA) Canine Vaccination Guidelines) |
| Kitten series start age | 6–8 weeks (American Association of Feline Practitioners (AAFP) Vaccination Guidelines) |
| Puppy/kitten booster interval | Every 2–4 weeks until ~16 weeks old (AAHA and AAFP guidelines) |
| Rabies vaccine (dogs & cats) | First dose at 12–16 weeks; booster schedule set by local law (Varies by state/municipality and vaccine license) |
| Adult core vaccine frequency | Every 3 years for most core vaccines after initial series (AAHA Canine Vaccination Guidelines; AAFP Feline Vaccination Guidelines) |
| Kennel cough vaccine type | Non-core; recommended for dogs in boarding, daycare, or dog parks (AAHA guidelines) |
Puppies typically start their core series around 6–8 weeks of age, with boosters given every 2–4 weeks until approximately 16 weeks old. Rabies vaccine is usually given at 12–16 weeks. A booster is then given at one year of age.
Kittens generally follow a similar structure: FVRCP shots beginning around 6–8 weeks, repeated every 3–4 weeks until 16 weeks, and rabies given at or after 12 weeks depending on local regulations and the vaccine label.
If you've just brought home a young animal, your pet's first year guide covers what to expect at early vet visits, feeding milestones, and much more.
Rescue and Shelter Pets May Have Different Records
If you've adopted a pet with incomplete or unknown vaccination history, your vet may recommend restarting certain vaccine series or running titer tests to check existing immunity. Don't assume prior vaccinations are current — always bring whatever records you have to your first vet appointment so a plan can be tailored to your pet's actual situation.
Adult Boosters and Senior Pet Considerations
Once the puppy or kitten series is complete and the one-year booster is done, most adult pets move to a less frequent schedule. Rabies boosters are governed by local law and the specific vaccine used — some are licensed for one year, others for three years. Core combination vaccines (DHPP for dogs, FVRCP for cats) are often given every three years in healthy adults, though your veterinarian may recommend annual assessment visits regardless.
~90%
Herd immunity threshold for rabies in dog populations
The World Health Organization estimates that vaccinating approximately 70–90% of a dog population can interrupt rabies transmission.
3 years
Typical adult booster interval for core vaccines
AAHA and AAFP guidelines support triennial (every three years) core booster schedules for healthy adult dogs and cats after their initial series.
As pets age, their immune systems and overall health needs change. Senior dogs and cats may still require regular boosters, but your vet might also re-evaluate which non-core vaccines remain appropriate given changes in lifestyle or health status. Wellness exams become increasingly important — vaccines are just one part of that picture.
To understand how veterinary priorities shift for older animals, read our article on senior pet veterinary care. For the full picture of care across all life stages, the end-to-end pet care overview is a helpful companion resource.
This article provides general educational information about pet vaccination and is not a substitute for personalized veterinary advice. Always consult a licensed veterinarian to determine the vaccination schedule that is right for your individual pet.