The C3 and C7 puppy vaccination schedule sets out exactly when a new puppy needs each core vaccine, running from the first shot at six to eight weeks through to full protection at around eighteen weeks.
For new puppy owners on Sydney’s Lower North Shore, working out which vaccine is due when, and why the C3 and C7 codes matter, is often the first real decision of puppy ownership.
At Pet Medical Milsons Point, we walk new owners through this schedule at every early puppy visit, and this guide sets out the same week-by-week path we use in the clinic.
Why Puppies Need a Vaccination Schedule at All
A puppy is born with some protection from its mother, passed on through her first milk. That protection fades gradually over the first weeks of life, and it fades at a different rate in every puppy, which is why a single vaccine at a single age cannot cover every puppy safely.
Giving a series of doses, spaced a few weeks apart, closes that gap so there is no point where a puppy is left unprotected while still too young for the vaccine to work fully. This is the reason the schedule exists as a series rather than a single visit.
This staged approach is also why missed or delayed appointments matter more than owners sometimes expect. A puppy who is a few weeks late for a dose is not simply a few weeks behind.
The gap in protection widens because maternal antibodies keep fading regardless of the calendar, and a delayed dose still has to do the same job of building immunity from wherever the puppy’s own protection has dropped to by that point.
Keeping doses close to the recommended windows, rather than treating them as flexible, is one of the simplest things an owner can do to keep the schedule working as intended.
The Puppy Vaccination Schedule, Week by Week
Six to Eight Weeks, the First C3
The first vaccine most puppies receive is a C3, covering three core diseases: parvovirus, distemper, and canine hepatitis, caused by an adenovirus. These three diseases are the ones every puppy in Australia is protected against as standard, regardless of lifestyle. This first dose is given as early as six weeks in some cases, though eight weeks is common, depending on when a puppy leaves its breeder or previous home.
Ten to Twelve Weeks, Second Dose: First C7
The second core dose steps a puppy up from a C3 to a C7, adding protection against kennel cough, caused by Bordetella bronchiseptica and canine parainfluenza, and against leptospirosis. This is also the stage where many puppies start their first supervised outings, which is covered further below.
Fourteen to Sixteen Weeks, Third Dose: Completing the C7
The third and final core dose locks in long-term protection against parvovirus, distemper, and hepatitis, and repeats the C7 to complete the kennel cough and leptospirosis coverage. From this point, a puppy that has had all three visits on schedule is considered fully covered for the core diseases, kennel cough, and leptospirosis.
Sixteen to Eighteen Weeks: Confirming Full Coverage
Because the second and third core visits now include the C7, most puppies on this schedule are already covered for leptospirosis by sixteen weeks, alongside parvovirus, distemper, hepatitis, and kennel cough. This visit is where we confirm that all three doses have been given on schedule and that your puppy is considered fully covered.
C3 or C7: Which Does My Puppy Need?
Whether a puppy needs a C3 alone or the fuller C7 course depends on how much contact they will have with other dogs, and where. A puppy that will attend puppy school, visit dog parks, or stay in boarding will usually need the added kennel cough and leptospirosis protection in a C7, since those settings carry higher exposure.
A puppy with a quieter, more contained routine may not need it at the same stage. Our vets make this call at your puppy’s vaccination appointment based on your puppy’s actual routine, not a blanket rule applied to every dog.
Factors we weigh when recommending a C3 or C7 course for a specific puppy:
- Whether your puppy will attend puppy school, dog parks, or boarding
- How much day-to-day contact your puppy has with other dogs
- The specific conditions in your part of Sydney
- Your puppy’s breed and any known health considerations
- What protection your puppy’s breeder or previous vet has already given
What This Means for Puppy Socialisation and Going Out
One of the most common questions new owners ask is when a puppy can start going for walks or meeting other dogs. Full protection is not complete until after the final core dose, but waiting until then to begin any socialisation at all can create its own problems, since the early weeks are also the most important window for a puppy to learn confidence around people, sounds, and other animals.
We cover this balance in detail, including safe ways to start socialising before a puppy is fully covered, in our main puppy vaccination guide.
Talk to Our Team About Your Puppy’s Schedule
Every puppy arrives on a slightly different timeline, depending on their age when they come home and what they have already had.
If you are not sure where your puppy sits in the schedule, or which vaccine is due next, get in touch with our team, and we will confirm the right plan at your puppy’s next visit.
Frequently Asked Questions
The puppy vaccination schedule in Australia runs from a first C3 vaccine at six to eight weeks, through a second dose at ten to twelve weeks that steps up to a C7 for kennel cough and leptospirosis protection, to a final dose at fourteen to sixteen weeks that repeats the C7 and completes the core course.
A C3 vaccine covers three core diseases: parvovirus, distemper, and canine hepatitis. A C7 covers those same three diseases plus kennel cough, caused by Bordetella bronchiseptica and canine parainfluenza, and leptospirosis, a bacterial infection more relevant for puppies with regular contact with other dogs or exposure to shared outdoor areas.
A puppy is generally considered fully vaccinated for the core diseases after the third and final dose, usually given between fourteen and sixteen weeks of age, provided the earlier doses were given on schedule.
Supervised, low-risk socialisation can often begin before the full course is finished, but the right balance depends on your puppy’s individual schedule and should be discussed with your vet rather than judged by age alone.
At Pet Medical Milsons Point, leptospirosis protection is included as standard in the C7 given at the second and third puppy visits, rather than offered as a separate, optional vaccine. If your puppy has already had part of their course elsewhere, our vets will confirm exactly what they’ve had before recommending next steps.
The cost of a puppy vaccination course depends on how many visits your puppy needs and which vaccines are recommended for their circumstances. Contact our reception team and they can talk you through what your puppy’s course involves before you book.