Dog Vaccines: Core and Optional
Which vaccines dogs need: core vaccines for every dog, noncore ones chosen by lifestyle, the puppy series, boosters for adults and why rabies follows local law, from the Merck Veterinary Manual. A reading guide, not veterinary advice.
AI illustration This is a reading guide to published vaccine recommendations. Which vaccines your dog needs, and when, depends on its age, health, lifestyle and where you live, and rabies is set by local law; your vet sets the schedule. Guidelines are revised from time to time, so ask your vet what is current.
The short answer: every dog gets the core vaccines, and some also get noncore vaccines chosen by where they live and what they do. The Merck Veterinary Manual sums up the canine guidelines in its section on preventive care like this:
| Core: for every dog | Noncore: by lifestyle and risk |
|---|---|
| Distemper | Bordetella bronchiseptica (part of kennel cough) |
| Parvovirus | Leptospirosis |
| Adenovirus-2 (protects against canine hepatitis) | Lyme disease (Borrelia burgdorferi) |
| Rabies | Canine influenza |
Merck adds that a coronavirus vaccine exists but is no longer recommended. The pet owner version says core vaccines are recommended by nearly all vets, and vaccines such as Lyme or Bordetella matter in certain areas (Merck).
The Puppy Series
Puppies get some protection from their mother at birth and through her milk. Vaccines don’t work well until that protection fades, so puppies need a series of doses (Merck):
- Distemper, parvovirus and adenovirus-2 come as one combination vaccine. It usually starts at 6 to 8 weeks and is repeated every 2 to 4 weeks until the puppy is over 16 to 20 weeks old.
- Rabies: the age of the first dose, and how often boosters follow, are set by state or local law. A killed rabies vaccine comes in 1-year and 3-year versions.
- Noncore vaccines are added as your vet advises.
Until the series is finished, Merck advises keeping the puppy away from unvaccinated dogs and from dogs whose vaccine history you don’t know. Parvovirus, one of the diseases this protects against, is covered in our guide to diarrhea in dogs.
Boosters for Adult Dogs
For the core combination vaccine, Merck gives the guideline schedule:
- A first booster no later than one year after the last puppy dose.
- Then boosters at intervals of three years or more.
Many practices have adopted this three-yearly protocol, Merck notes. It sets this next to the historical concern about over-vaccination, mentioning some correlation between vaccination and immune-mediated disorders in dogs. The pet owner version adds that some vaccines need boosters only every few years and others every year, and that your vet will tell you which.
What to Tell Your Vet
To choose noncore vaccines, your vet needs to know how your dog lives:
- Kennels, shelters, dog parks, classes or shows: canine influenza is highly contagious, and Merck notes outbreaks are most common where dogs are in close contact, such as kennels, shelters and dog parks (Merck).
- Ticks: walks in tick country, where Lyme disease occurs.
- Water and wildlife: leptospirosis bacteria survive for long periods in swamps, streams and rivers. Dogs catch it through contaminated urine or water, bite wounds, or eating infected animals (Merck).
- Travel, including to other states or countries with different rabies rules.
For cats, see cat vaccines.
