Cat vaccination schedule: what the dates mean and what to track

A kitten's first vaccinations are given as a series of doses over several weeks, not as one appointment, and the reason is maternal antibody.

A newborn receives antibodies from their mother. Merck describes this passive immunity as passing via the placenta or the first milk, protecting the newborn while their own immune system develops. It also blocks vaccination, and it fades gradually rather than on a fixed day — at a different time in different kittens. So young animals need a series of vaccinations as the protection they receive at birth from their mother decreases and their own immune systems develop. The series covers an unknown date; it is not a set of top-ups.

The global structure (WSAVA 2024)

For the core components — FPV, FHV and FCV — WSAVA's 2024 guidelines set out the series as beginning at 6–8 weeks, repeating every 2–4 weeks, and continuing until 16 weeks of age or older. Because the start age and the interval both vary, the number of doses varies too. WSAVA's 2024 guidance then includes a subsequent FPV/FHV/FCV core dose at 26 weeks of age or older — about 6 months, intended to narrow the remaining window of susceptibility from maternally derived antibody interference. That applies to the core components named, not to every feline vaccine.

The North American specification (AAHA/AAFP)

For the parenteral (injected) FPV + FHV-1 + FCV schedules in the 2020 AAHA/AAFP guidelines, the same period is described as beginning no earlier than 6 weeks, repeating every 3–4 weeks until 16–20 weeks, with revaccination to be considered at 6 months rather than 1 year. ⚠️ The formulation matters: intranasal FHV/FCV schedules in the same guideline can carry different revaccination intervals, including annual ones.

Merck adds a practical point for the series period: keeping kittens away from unvaccinated cats until they have received the full series is important protection while the course is still incomplete.

Yes — indoor status changes the risk assessment; it does not by itself reduce vaccination need to zero. Indoor living is a real and relevant factor: AAHA and AAFP list lifestyle and environment among the things a feline risk assessment weighs, and lifestyle is exactly what "indoor" describes. But three things stop it being a simple answer.

First, indoor status does not remove the core classification of the globally relevant vaccines. WSAVA classifies FPV, FCV and FHV as core worldwide, and rabies as core where rabies is endemic. Other parts of a cat's vaccination plan can depend on geography, exposure and lifestyle — FeLV is an important example.

Second, "indoor only" is not the same as "never exposed". AAHA/AAFP explicitly notes that cats described as indoor-only may still be periodically exposed to other cats. That is enough to make "indoor" one input to a risk assessment rather than proof of zero exposure.

Third, rabies requirements also depend on local law and regulation, so indoor status alone cannot tell you what the legal requirement is where you live.

What an indoor lifestyle can legitimately change is the risk-based part of the plan — FeLV in an adult cat being the clearest example. That assessment is your veterinarian's, made for your cat. 🚫 None of this means an indoor cat needs every available vaccine.

The vaccination record is one of the few pieces of veterinary information an owner genuinely holds, and the one most often missing when it is needed — at a new practice, at a boarding cattery, when travelling, or in an emergency. For each entry:

• Which vaccine or antigen it was, as specifically as the record states
• The date it was given
• The next due or review date, if your veterinarian supplied one
• The practice and veterinarian who administered it
• Manufacturer, product name and batch or lot number, where these appear on the record
• Any reaction, and any instruction you were given to watch for or record one
• The injection site, if your practice records it

That list is not arbitrary. WSAVA's 2024 guidelines set out what the permanent medical record should capture at vaccination: the date administered, the identity of the person administering it, the vaccine name, the lot or serial number, the expiry date, the manufacturer, the anatomical site and the route — with adverse events recorded, and vaccination certificates indicating how long protection is expected to continue. Your practice keeps that full record; the fields above are the part worth having your own copy of.

Previous reactions matter especially. Any reaction to a vaccine, however mild it seemed at the time, is important history to tell your veterinarian before the next one — it is information only you are holding if it happened at home. Our guide to what to track when your pet seems different covers recording an observation so it is usable later.

Common, and not a dead end — rescued, stray, imported and rehomed cats are routine, and so are lost record cards.

Bring whatever documentation exists, even if partial or in another language: rescue or shelter paperwork, an import or travel document, a pet passport, previous practice details, a microchip number, or photographs of an old card. Add anything you were told verbally, marked clearly as unconfirmed. Then ask your veterinarian to establish the appropriate plan from the available history and current guidance. An incomplete history is still evidence, and usually better than assuming nothing was given.

From that point the record you keep is the reliable one — worth starting properly on day one.

Patter keeps your cat's vaccination schedule and history alongside the rest of their health context — daily checks, weight, nutrition, mood and vet visit information — against one profile. It tells you what is next, gives approaching and overdue notices, and explains why a given vaccine is relevant for your cat rather than only showing a date. See health in Patter and Patter for cats.

The boundary is the important part. Your veterinarian sets the schedule; Patter records it and makes it harder to overlook. Patter does not decide which vaccines your cat needs, does not set or override a due date your veterinary practice has given you, and does not issue rabies requirements for your country or region. A date in the app is a reminder of your veterinarian's plan — not a new medical recommendation the app has generated. See Patter and your veterinarian.