Core vaccines: the non-negotiables
The American Animal Hospital Association (AAHA) classifies certain vaccines as "core" — meaning every dog should receive them regardless of lifestyle or geography. These protect against diseases that are widespread, highly contagious, or fatal.
DHPP (Distemper, Hepatitis, Parainfluenza, Parvovirus)
Often called the "distemper combo" or "5-in-1," this is the backbone of your dog's vaccination protocol. It protects against four diseases in a single shot:
- Canine distemper — a viral disease affecting the respiratory, gastrointestinal, and nervous systems. Often fatal in unvaccinated puppies.
- Infectious canine hepatitis (Adenovirus-2) — targets the liver. The vaccine uses Adenovirus-2, which cross-protects against Adenovirus-1.
- Parainfluenza — a respiratory virus that contributes to kennel cough. Often bundled in the combo shot.
- Parvovirus — extremely contagious and frequently fatal in puppies. Attacks the intestinal lining. One of the most important reasons to stay on schedule with puppy vaccines.
Schedule: Puppies get a series of three to four doses starting at 6–8 weeks of age, given every 2–4 weeks until 16 weeks old. After that, a booster at one year, then every three years. Your vet may adjust the timing based on your puppy's specific circumstances — follow their guidance.
Rabies
Rabies vaccination is required by law in all 50 U.S. states for dogs. It's the only vaccine that's universally mandated because rabies is fatal in both animals and humans, and there's no treatment once symptoms appear.
- First dose: typically given between 12 and 16 weeks of age.
- Booster: one year after the first dose, then every one or three years depending on the vaccine product used and your state's law.
- Legal note: your vet issues a rabies certificate with each vaccination. Keep this — you'll need it for licensing, boarding, travel, and any animal bite incident.
Lifestyle vaccines: depends on your dog's world
These aren't less important — they're just targeted. Your vet recommends them based on where your dog lives, travels, and spends time. The AAHA calls these "non-core" vaccines, but a better mental model is "risk-based."
Bordetella (kennel cough)
Protects against Bordetella bronchiseptica, the most common bacterial cause of kennel cough. Required by almost every boarding facility, doggy daycare, and grooming salon. If your dog interacts with other dogs in any group setting, they need this.
Schedule: given as early as 8 weeks. Available as an injection, nasal spray, or oral form. Boosted annually (some facilities require it every 6 months).
Leptospirosis
Caused by Leptospira bacteria found in water contaminated by wildlife urine. Affects the kidneys and liver. It's zoonotic — dogs can transmit it to humans. Increasingly recommended even in suburban areas, because wildlife (raccoons, rodents, deer) bring it everywhere.
Schedule: two initial doses 2–4 weeks apart, then annual boosters. Often added to the DHPP combo as "DHLPP."
Lyme disease
Transmitted by deer ticks (Ixodes scapularis in the East, Ixodes pacificus on the West Coast). Causes joint pain, fever, kidney problems, and in severe cases, kidney failure. Most relevant in the Northeast, upper Midwest, and Pacific coast — but tick ranges are expanding.
Schedule: two initial doses 2–4 weeks apart, then annual boosters. Usually recommended alongside tick prevention medication, not as a replacement for it.
Canine influenza (H3N2 and H3N8)
Dog flu is highly contagious in group settings. Outbreaks pop up regionally, and some boarding facilities and daycares now require it. Two strains circulate — H3N2 (more common in recent years) and H3N8. Bivalent vaccines cover both.
Schedule: two initial doses 2–4 weeks apart, then annual boosters.
Puppy series vs. adult boosters
The reason puppies get multiple rounds of vaccines isn't because one dose "doesn't work." It's because maternal antibodies — passed from the mother through nursing — can interfere with the vaccine's ability to trigger the puppy's own immune response. Since those maternal antibodies fade at different rates for each puppy, the series ensures at least one dose lands in the window where it can take effect.
Typical puppy vaccination timeline
| Age | Vaccines |
|---|---|
| 6–8 weeks | DHPP (first dose), Bordetella (if boarding/daycare planned) |
| 10–12 weeks | DHPP (second dose), Leptospirosis (first dose), Lyme (first dose, if in tick area) |
| 12–16 weeks | DHPP (third dose), Rabies (first dose), Leptospirosis (second dose), Lyme (second dose) |
| 16 weeks+ | DHPP (fourth dose if series started early), Canine influenza (if needed) |
Adult booster schedule
| Vaccine | Frequency |
|---|---|
| DHPP | Every 3 years after the 1-year booster |
| Rabies | Every 1 or 3 years (depends on state law and vaccine type) |
| Bordetella | Annually (some facilities require every 6 months) |
| Leptospirosis | Annually |
| Lyme | Annually (if in tick-endemic area) |
| Canine influenza | Annually (if risk factors present) |
What about titer testing?
A titer test measures antibody levels in your dog's blood to check if they still have immunity from a previous vaccine. Some owners and vets use titers to avoid unnecessary boosters for DHPP. AAHA acknowledges titer testing as an acceptable alternative for determining whether revaccination is needed for distemper and parvovirus.
Important caveats: titer testing doesn't replace rabies vaccination (it's legally required regardless of titer results in most states). And it costs more than the vaccine itself — typically $150–$300 for the blood draw plus lab work, compared to $25–$50 for the DHPP booster. Talk to your vet about whether it makes sense for your dog's situation.
When vaccine records actually matter
You'll need your dog's vaccination records more often than you think:
- Boarding and daycare: Every facility requires proof of current rabies, DHPP, and Bordetella. Many now require canine influenza.
- Pet licensing: Your county or city requires a current rabies certificate to issue or renew a dog license.
- Travel: Interstate travel requires a health certificate (usually within 10 days). International travel has even stricter requirements with specific timing windows.
- New vet: When you switch vets or visit a specialist, they need the full vaccination history to avoid unnecessary revaccination or missed boosters.
- Emergency vet visits: Knowing vaccination status helps the ER vet make faster decisions — especially regarding diseases like parvo or rabies exposure.
The bottom line
Your dog's vaccine schedule isn't one-size-fits-all, and that's OK. Core vaccines (DHPP and rabies) are universal. Everything else depends on your dog's exposure risk — where they live, where they go, and what they do. Your vet is the right person to build the specific protocol for your dog.
What you can control: keeping the records organized so you're never scrambling for a certificate at 7 AM before a boarding drop-off.