💉 Cat Vaccination Schedule Calculator

Core vs. Non-Core Cat Vaccines

Core vaccines are recommended for every cat, indoor or outdoor, because the diseases are common or severe enough to warrant protection regardless of lifestyle. These are FVRCP (feline viral rhinotracheitis, calicivirus, panleukopenia) and rabies, which is legally required in most areas.

FeLV (feline leukemia) sits in a gray zone — it's considered core for kittens (since risk is highest early in life and exposure history is often unknown) but becomes non-core for adult indoor-only cats with no exposure to unknown-status cats. Outdoor cats or those living with FeLV-positive cats should stay on the FeLV vaccine schedule.

Why "Indoor Only" Doesn't Mean "No Vaccines Needed"

It's a common assumption that strictly indoor cats don't need much in the way of vaccination. In practice, indoor cats still need core vaccines. Rhinotracheitis and calicivirus are highly contagious respiratory viruses that can be carried in on clothing or by other pets, and panleukopenia (feline distemper) can survive on surfaces for a long time. Rabies exposure, while rare for indoor cats, is still possible through an accidental escape or an unvaccinated animal getting into the home — and it's the one vaccine where the legal requirement doesn't bend based on lifestyle.

Where lifestyle genuinely changes the calculation is with FeLV and other exposure-driven vaccines — that's where indoor-only status meaningfully reduces what's needed.

Adult Booster Schedules

After the kitten series and a one-year booster, many vets move FVRCP to a 3-year schedule for healthy adult cats. Rabies boosters follow local law and vaccine type — often 1 or 3 years. FeLV, when still indicated, typically follows an annual or every-other-year booster schedule depending on ongoing exposure risk.

If your cat's vaccine history is unknown — common with adopted or rescued cats — vets will often restart with a fresh series rather than assume partial protection, since there's no reliable way to confirm what was actually given previously.

Why Deworming Takes More Than One Dose

A single deworming treatment kills the adult worms living in the intestines at that moment — but it doesn't reach eggs or larvae still migrating through other tissue or that haven't hatched yet. Over the following one to two weeks, those immature parasites mature and move back into the intestine, which is exactly why the CAPC (Companion Animal Parasite Council) schedule repeats every 2 weeks during early kittenhood — it's timed to catch each new wave before it can reproduce again.

Kitten schedules commonly start about a week later than puppy schedules (around 3 weeks old rather than 2). Puppies can be born already infected because roundworm larvae can reactivate in the mother and cross the placenta before birth — kittens don't share this route, only transmission through nursing, so their exposure starts slightly later.

Roundworms and Human Health

Roundworms are zoonotic — they can transfer to people, most commonly through accidental ingestion of contaminated soil or surfaces, and children are at particular risk if they play in areas a pet has defecated. Consistent deworming on schedule, plus prompt litter box cleanup, protects your household as well as your cat.

Pair Deworming With Fecal Exams

CAPC recommends fecal examinations at least twice a year for adult cats (more often for kittens or higher-risk lifestyles like outdoor access or hunting), separate from routine deworming itself. A fecal exam identifies which parasites, if any, are actually present, which helps your vet confirm the deworming schedule is working rather than assuming it is. This calculator covers dates and intervals only — your vet will determine the specific product and dose appropriate for your cat's weight and health.

Frequently Asked Questions

What vaccines does an indoor-only cat need?

Even strictly indoor cats need core vaccines — FVRCP and rabies — since exposure can happen through open windows, other pets, or accidental escapes, and rabies is legally required in most areas. FeLV is generally only needed for cats with outdoor access or exposure to FeLV-positive cats.

At what age do kittens start vaccines?

Kittens typically start their FVRCP series at 6–8 weeks old, with follow-up doses every 3–4 weeks until at least 16 weeks. Rabies is usually given at 12–16 weeks, and FeLV testing/vaccination is often recommended in the same window for at-risk kittens.

Does my cat need FeLV vaccine every year?

FeLV vaccine schedules vary — an initial two-dose series is followed by a booster at one year, and then annual or every-other-year boosters depending on ongoing outdoor exposure. Indoor-only adult cats with no FeLV-positive housemates may not need continued boosters — ask your vet.

How often should kittens be dewormed?

Per CAPC guidelines, kittens are commonly dewormed starting around 3 weeks old (about a week later than puppies), repeated every 2 weeks until about 8-9 weeks, then monthly until 6 months old, then quarterly as an adult. This schedule targets the parasite life cycle, not just a single treatment.

Why can't one deworming treatment finish the job?

A single dose kills adult worms present at that moment but doesn't reach eggs or larvae still migrating through other tissue. Those immature parasites mature and return to the intestine over the following one to two weeks, which is why repeated doses on a schedule — not a single treatment — are needed to fully break the cycle.

Can worms in cats spread to humans?

Yes — roundworms are zoonotic and can transfer to people, most commonly through accidental contact with contaminated soil or litter. Children are at particular risk, which is part of why consistent deworming and prompt litter box cleanup both matter.

Do indoor-only adult cats still need regular deworming?

Yes, though risk is lower than for outdoor cats. CAPC recommends fecal exams at least twice a year for adult cats and broad-spectrum deworming on a regular schedule, since some parasites can still be introduced indoors (fleas carrying tapeworm segments, for example). Many cats on a monthly flea/heartworm preventive that also covers intestinal parasites are effectively covered more often than a quarterly minimum.

Can I determine my cat's exact dewormer dosage from an online calculator?

No — dosage depends on your cat's weight, the specific product, and your vet's judgment about your cat's individual parasite risk, so it should always come from your veterinarian rather than a general online tool. This calculator covers timing and intervals only.