Which vaccinations does a cat need?

Vaccination shows the immune system a harmless version of a disease so it can defend itself later. It prepares the body; it does not treat a disease the cat already has.

Core vaccines are the ones every cat should have, whatever its lifestyle, because they protect against serious, often life-threatening disease. They cover feline panleukopenia (parvovirus, FPV), feline calicivirus (FCV) and feline herpesvirus-1 (FHV-1). The last two are the main viruses behind cat flu.

Rabies counts as core where rabies occurs, even when no law requires it. Elsewhere it is a non-core vaccine, needed mainly for travel or where the law asks for it.

Feline leukaemia (FeLV) is treated differently by different guidelines. WSAVA 2024 and AAHA/AAFP 2020 call it core for kittens under one year (WSAVA: where FeLV is common), and non-core for adults with a real risk, such as outdoor access.

Other non-core vaccines are for cats with a specific risk: Chlamydia felis and Bordetella bronchiseptica. FIV is restricted to cats at very high risk and is not recommended routinely. Vaccines against feline infectious peritonitis (FIP) are not recommended by WSAVA, AAFP or Cornell.

Vaccines come in different types: modified-live or killed, with or without adjuvant, injected or given in the nose. They differ in speed, length of protection and safety, so products from different makers are not interchangeable.

Modern guidance is individual: each cat gets the core vaccines, plus only the non-core ones its life calls for, and none more often than needed. A fixed yearly booster for every vaccine is no longer the advice.

Panleukopenia (cat distemper, kattenziekte) is a highly contagious virus of the gut and immune system. It causes fever, vomiting, diarrhoea, loss of appetite and dehydration. Kittens are hit hardest and sudden death is common. It is a different virus from canine distemper.

The virus is carried in faeces and can stay infectious in the environment for months or even a year. People bring it in on shoes and clothing, so indoor cats can be exposed too.

Cat flu (herpesvirus and calicivirus) causes sneezing, eye and nose discharge, mouth ulcers and sometimes pneumonia. Deaths are rare, but a rare virulent calicivirus strain can be deadly. Herpesvirus stays in the body for life and can flare up under stress.

Rabies is a fatal virus of the nervous system, spread mostly by bites. It can infect people. There is no cure once signs appear.

Feline leukaemia virus spreads mainly through close contact, especially saliva, and is a leading cause of virus-related deaths in cats. Only cats that test negative are vaccinated.

Vaccinated cats are not completely immune. Panleukopenia vaccines give strong, long-lasting protection. Herpesvirus and calicivirus vaccines are weaker: a vaccinated cat can still catch cat flu, but the illness is usually milder.

A kitten gets antibodies from its mother's milk. They protect it early on, but they also block the vaccine. They fade at different speeds in different kittens, and in some they are still there at 16 to 20 weeks.

Because nobody can tell when the blocking stops, kittens get a series of doses. WSAVA 2024 says to start at 6 to 8 weeks, repeat every 2 to 4 weeks, and give the last dose at 16 weeks or older.

Stopping the course too early is thought to be the most common reason a kitten vaccination fails. In one German field study 36.7 percent of kittens did not respond despite three doses, so one vaccine does not mean a protected kitten.

A kitten is not fully protected until a few weeks after the last dose of the course. Until then, keep it away from cats outside the home.

Live panleukopenia vaccines are avoided in very young kittens (under 4 to 6 weeks) and in pregnant cats, because they can affect the developing brain (cerebellum). Vets then use other vaccine types or time things differently.

After the kitten course, guidelines advise one booster at about 6 months to a year, then the core vaccine against panleukopenia no more often than every 3 years.

Herpesvirus and calicivirus protection is shorter. WSAVA and ABCD say a low-risk indoor cat can have these every 3 years, while a higher-risk cat (goes outdoors, multi-cat home, boarding) may be boosted yearly.

Most non-core vaccines last about a year. FeLV boosters for adults are every 1 to 3 years depending on the vaccine and the risk; Bordetella and Chlamydia need yearly boosters where they are used at all.

Rabies boosters follow the vaccine label and local law, usually every 1 to 3 years.

An adult cat that was never vaccinated, or has an unknown history, is treated like an unvaccinated cat: usually two core doses 3 to 4 weeks apart. WSAVA counts one live panleukopenia dose as protective, while makers and some guidelines use two.

A cat that finished the kitten course but is overdue needs one booster, not a restart, according to WSAVA and AAFP. Some charities advise restarting if the lapse is long, so ask the vet.

Vaccination should be part of a yearly health check, not a separate visit. The vet looks at weight, teeth, skin and early signs of illness and decides which vaccines are due. This check is advised even when no vaccine is due that year.

Yes. The core vaccines are advised for indoor and outdoor cats alike. Viruses such as panleukopenia and calicivirus survive for months and are carried in on shoes, clothes and shopping bags.

Strictly indoor cats may get no natural boosting from outside exposure, so their immunity can fade if vaccines lapse.

What indoor cats may skip is mostly non-core vaccines. A single indoor cat with no contact with other cats has no appreciable FeLV risk, but a catio, supervised outdoor time or a new cat in the home changes that.

Low-risk indoor cats are the ones guidelines allow to be boosted every 3 years for all core vaccines.

A blood test can measure antibodies and show whether a vaccine has worked or is still working. Testing from about 20 weeks of age can check the response to a kitten course.

It works well for panleukopenia. ABCD says an adult with enough antibodies does not need a panleukopenia booster, and a test can be an alternative to revaccination, for example for cats with a past vaccine reaction or an unknown history.

It works much less well for cat flu viruses. Antibody levels do not reliably predict protection against herpesvirus and calicivirus, because cats can also be protected by other parts of the immune system.

A titre test is not proof of protection on its own, and the AAFP prefers fixed intervals. Labs use different methods with no international standard, and routine testing is still costly and not offered by every practice.

In one German study of 112 healthy adult cats, 64.3 percent already had protective panleukopenia antibodies before a booster. The study was small and paid for by a vaccine maker, so it is a question for the vet, not a rule.

Most reactions are mild and pass in a day or two: tiredness, less appetite, a slightly raised temperature, and a sore or small lump at the injection spot.

A small, painless lump at the injection site is common and usually goes away within about four weeks.

Allergic reactions are rare. Signs are facial swelling or itching, vomiting, diarrhoea, breathing trouble or collapse. They need a vet at once. If a cat once had one, the vet weighs whether and how to vaccinate again.

Injection-site sarcoma is a rare tumour that can grow where an injection was given, months or years later. Vaccines are one cause; other injections can also cause it. Estimates differ: about 1 in 5,000 to 12,500 vaccinated cats (WSAVA), well below 1 in 10,000 doses (AAFP), and older UK and US figures from 1 in 1,000 to 1 in 50,000. No single figure is settled.

Vets reduce the harm if one occurs: they avoid the scruff and the space between the shoulder blades, inject in the lower limbs or tail, rotate the site, and write down where each vaccine went. This does not lower the chance of a tumour; it makes early detection and surgery easier.

Large studies found no link between a particular brand, needle size or practice set-up and sarcoma. Skipping vaccines is not a safe way to avoid it, because the diseases they prevent still cause outbreaks.

Check your cat by stroking it regularly. A lump at an injection spot that is still there after 3 months, is larger than 2 cm, or keeps growing 1 month after the injection (the 3-2-1 rule) needs a vet. Treatment is usually wide surgery, often with radiotherapy.

Do not vaccinate a pregnant cat with a live vaccine unless the vet advises it, and tell the vet if the cat has FeLV or FIV, since killed vaccines are then preferred.

Travelling abroad usually needs a microchip and a rabies vaccination, recorded in a passport or health certificate. Rules and age limits differ per country and can involve waiting times of weeks, so ask early. What applies for travel within Europe is in your country's block.

Some countries also ask for a rabies antibody test, and a few ask for it before departure. The microchip must be in place before or on the day of the first rabies vaccination written in the passport.

Boarding catteries usually ask for up-to-date core vaccines and often a booster within the last 12 months. A booster 7 to 10 days before boarding may be advised, especially if the cat was not vaccinated in the past year. Ask early.

FeLV: for kittens, and for adults who go outdoors or meet cats of unknown status. A negative test comes first.

Chlamydia: mainly for multi-cat homes where the infection was confirmed. It reduces signs but does not prevent infection.

Bordetella: a nose vaccine for cats at specific risk, such as shelters. It must never be injected.

FIV: not recommended because the vaccine makes later FIV tests unreliable and protection is incomplete. FIP: not recommended.