Puppy Vaccination & Deworming Schedule: The First-Year Plan

The first year is a sequence of dated decisions, not a slow ramp. The schedule below is the AAHA-aligned core framework; your veterinarian adjusts exact dates to your puppy's age at intake and regional disease risk.

| Age | Core vaccine due | Non-core (lifestyle) options | Deworming | |---|---|---|---| | 6–8 weeks | DAPP dose 1 (distemper, adenovirus, parvovirus, parainfluenza) | — | Pyrantel/fenbendazole — start deworming if not begun at 2 weeks | | 9–11 weeks | DAPP dose 2 | Leptospirosis dose 1 and Bordetella if lifestyle risk (boarding, daycare, dog parks) | Deworm again — roundworm/hookworm reinfection is the norm at this age | | 12–15 weeks | DAPP dose 3; rabies at 12–16 weeks | Leptospirosis dose 2 (3–4 weeks after dose 1); canine influenza if regional outbreak | Deworm; begin year-round broad-spectrum parasite + heartworm prevention | | 16–18 weeks | DAPP final dose (must be at or after 16 weeks to count) | Lyme dose 2 if started; Lyme is regional (tick-endemic areas only) | Monthly preventive continues; transition to monthly product | | ~6 months | — | Spay/neuter discussion with your veterinarian | Fecal recheck — confirm parasite clearance before relaxing cadence | | 12–16 months | First adult boosters (DAPP + rabies 1-year, then 3-year cycle) | Lifestyle non-core boosters annually if risk persists | Year-round monthly prevention for life |

Print this and put it on the fridge. The most common preventable problem described by owners is a puppy that got one DAPP shot at 8 weeks, went 5 weeks without the next, and was treated as protected — the series is the protection, and the final dose at or after 16 weeks is the dose that closes the maternal-antibody window. A dose given at 15 weeks does not substitute; AAHA is explicit that the series must extend to at least 16 weeks because some puppies retain interfering maternal antibody that late.

Maternal antibodies passed in the dam's first milk protect a puppy for an unknown number of weeks — sometimes 6, sometimes 16 — and while present they also neutralize vaccine antigen, so an early dose can "take" in one littermate and fail in another. Repeating every 3–4 weeks until 16+ weeks is a statistical net: you cannot test the exact day maternal antibody drops in an individual puppy without titer testing, so you vaccinate on a cadence that catches every puppy as its window opens. Spacing doses more than 4 weeks apart leaves a longer unprotected gap; closer than 2 weeks can blunt the response. Stay inside the 3–4 week band.

Book the first veterinary visit within the first 3–5 days, before problems appear, not after. That visit sets a weight baseline (healthy puppies gain steadily — a flat or dropping weight is an early warning), confirms or starts the vaccine and deworming schedule on your puppy's actual age, and is the standard point to run a fecal exam because intestinal parasites are near-universal in puppies and not always visible in stool. Bring a fresh fecal sample if asked. Confine a new puppy to a small, cleanable area at first — a flooded whole-house environment makes house-training slower and makes it harder to monitor stool, which in the parvo-risk window is something you want to be watching daily.

Socialization is the first-year decision with the shortest deadline and the one most directly in tension with vaccination. The AVSAB position statement places the canine sensitive period at roughly 3 to 14 weeks, closing around 16 weeks — which falls before the final DAPP dose. Waiting until full immunity to begin socializing means missing the window entirely, and AVSAB's stated position is that behavioral problems, not infectious disease, are the leading cause of death for dogs under three years because under-socialized dogs are surrendered or euthanized for fear and aggression. So the answer is not "wait"; it is "socialize on controlled ground."

How to socialize safely before the series is complete, because each rule lowers a specific parvo exposure vector:

For physical exercise, keep it low-impact while growth plates are open: short, frequent free-play and exploration over forced running or long jogs, because repetitive high-impact loading on an immature skeleton — especially in large breeds — is a recognized contributor to joint disease. A rough guide some veterinarians use is roughly 5 minutes of structured walk per month of age, twice daily, adjusted to the individual.

Core vaccines (AAHA 2022). DAPP — also written DHPP/DA2PP — protects against canine distemper virus, adenovirus (hepatitis), parvovirus, and parainfluenza. Parvovirus is the one that fills emergency wards: it attacks the intestinal lining and bone marrow, and in an unvaccinated puppy it is frequently fatal without intensive care. The series runs every 3–4 weeks from 6–8 weeks to a final dose at 16 weeks or later, then a booster at ~1 year, then every 3 years. Rabies is a separate core vaccine given once at 12–16 weeks (legally required in nearly all US jurisdictions regardless of lifestyle), boosted at 1 year, then on a 1- or 3-year cycle by local law.

Non-core (lifestyle) vaccines. These are risk-based, not universal: leptospirosis (a 2-dose primer 3–4 weeks apart, recommended in most of the US now because lepto is zoonotic and increasingly urban), Bordetella and canine parainfluenza/influenza (for dogs that board, attend daycare, or visit dog parks), and Lyme (tick-endemic regions only). Decide each with your veterinarian based on where you live and how the dog will live.

Titers. A vaccine titer is a blood test measuring antibody to distemper and parvovirus. AAHA's position is that titers can confirm response after the puppy series is complete, but a titer does not replace the puppy series — a young puppy with maternal antibody can show a number that does not reflect durable immunity. Titers are most useful for adult booster decisions, not for skipping puppy doses.

Deworming. Most puppies are infected with roundworms or hookworms via the dam, before birth or through milk, so deworming is not contingent on a positive fecal — it is routine. The Companion Animal Parasite Council (CAPC) recommends deworming every 2 weeks from 2 weeks of age until 8–12 weeks, then monthly broad-spectrum prevention. Many of these parasites are zoonotic (roundworm larval migration in children is the reason this is not optional), which is also why fecal exams continue through the first year. Start year-round heartworm prevention by 12 weeks or as your veterinarian directs.

Vaccine reactions. Mild soreness, a low-grade temperature, or 24–48 hours of being subdued is normal and self-limiting. The reaction that needs action is anaphylactic or facial: it typically appears within minutes to a few hours.

See a veterinarian — emergency, do not wait and watch:

Call the same day: a single vomit or soft stool with a puppy that is otherwise bright, eating, and playing — but if a second sign appears, it moves to the emergency list above. Monitor at home and call if it does not resolve by next day: mild post-vaccine soreness or one quiet evening with normal eating. "When in doubt, ask your vet" applies — but the parvo triad above is the line at which doubt should already be resolved in favor of going in, because a puppy that is "a bit off" in the morning can be critically ill by evening.