How often do dogs need vaccines? Core and non core vaccines explained
Not every vaccine is yearly. Under the American Animal Hospital Association (AAHA) guidelines, after the puppy series and one booster within a year, the distemper, adenovirus and parvovirus combination vaccine is boosted every 3 years, the leptospirosis vaccine every year, and rabies as local law requires. Non core vaccines such as kennel cough, Lyme disease and canine influenza are given, usually yearly, only to dogs whose lifestyle or location puts them at risk.
Core and non core vaccines
The AAHA, whose canine vaccination guidelines are widely used by vets in North America, sorts vaccines into two groups:
- Core vaccines are recommended for all dogs, whatever their lifestyle, unless there is a specific medical reason not to vaccinate: canine distemper virus, canine adenovirus type 2, canine parvovirus type 2, leptospirosis and rabies. Leptospirosis was added to the core list in a 2024 update.
- Non core vaccines are recommended for some dogs based on lifestyle, geographic location and risk of exposure: Bordetella bronchiseptica (often part of "kennel cough" protection), canine Lyme disease, canine influenza and the Western diamondback rattlesnake toxoid. The AAHA notes that where a disease such as Lyme is common, local vets may treat that vaccine as core.
The puppy series
Puppies need several doses because antibodies passed on from their mother can block a vaccine from working. The AAHA's distemper guidance explains that these maternal antibodies decline over time and are usually gone by 12 to 14 weeks, which is why doses are repeated every 2 to 4 weeks until the puppy is over 16 weeks old (some vets prefer to give a final dose at 18 to 20 weeks where distemper risk is high).
| Vaccine | Puppies 16 weeks or younger | Dogs over 16 weeks (first time) | Boosters |
|---|---|---|---|
| Distemper, adenovirus, parvovirus (with or without parainfluenza) | At least 3 doses of a combination vaccine between 6 and 16 weeks, 2 to 4 weeks apart | 2 doses, 2 to 4 weeks apart | One dose within 1 year of the last initial dose, then every 3 years |
| Leptospirosis | 2 doses, 2 to 4 weeks apart, starting at 12 weeks | 2 doses, 2 to 4 weeks apart | One dose within 1 year, then every year |
| Rabies | As required by law | ||
| Bordetella (non core) | One intranasal or oral dose, or two injected doses, for dogs at risk | Yearly | |
| Lyme disease (non core) | 2 doses, 2 to 4 weeks apart | One dose within 1 year, then yearly | |
| Canine influenza (non core) | 2 doses, 2 to 4 weeks apart | One dose within 1 year, then yearly | |
Source: AAHA 2022 Canine Vaccination Guidelines, Table 2, as updated in 2024. These are general recommendations; vets adapt them to each dog and to vaccine labels.
So why does my dog see the vet every year?
Because some vaccines, such as leptospirosis and most non core vaccines, really are yearly, and because the AAHA recommends that each dog's vaccine needs be reassessed at least once a year as travel, lifestyle and local disease risks change. An annual visit is also the chance for a full health check, teeth, weight and parasite prevention. So a yearly appointment is normal, even if your dog does not get every vaccine every year.
On the 3 year interval for distemper, the AAHA says annual boosters are not necessary after the first adult booster. It also notes that longer immunity than 3 years has been suggested but is largely unsubstantiated in peer reviewed research, which is why it does not recommend going longer.
Overdue or unknown history
Adopted a dog with no records, or missed a booster? The AAHA's guidance is that the benefits of vaccinating outweigh the risks in most cases where vaccination history is unknown, summed up as "when in doubt, vaccinate". For rabies, follow local law. Your vet will advise on restarting a series.
Outside the US
The AAHA guidelines are written for North America. Which diseases are common, which vaccines are licensed, and the legal rules for rabies all differ by country, so your local vet's schedule may look a little different. The core idea is the same everywhere: protect every dog against the most serious widespread diseases, and add other vaccines based on real risk.
Frequently asked questions
Do dogs need vaccines every year?
Some do and some do not. Under the AAHA guidelines, leptospirosis and most non core vaccines are yearly, while the distemper, adenovirus and parvovirus combination is given every 3 years after the first adult booster. Rabies follows local law.
What are the core vaccines for dogs?
The AAHA lists canine distemper, canine adenovirus type 2, canine parvovirus, leptospirosis and rabies as core vaccines recommended for all dogs.
When is a puppy fully vaccinated?
The AAHA recommends repeating the combination vaccine every 2 to 4 weeks until the puppy is over 16 weeks old, followed by a booster within a year. Your vet will tell you when your puppy's course is complete.
Sources
- 2022 AAHA Canine Vaccination Guidelines (updated 2024), American Animal Hospital Association
- Recommendations for core and noncore canine vaccines, American Animal Hospital Association
- Key Vaccination: Canine Distemper Virus, American Animal Hospital Association
General education only, not veterinary advice. If you are worried about your dog, contact your vet; in an emergency, contact an emergency vet straight away.