Most of the illnesses that sweep through a colony of street cats are ones we can vaccinate against. Cat flu, which leaves cats sneezing and off their food. Panleukopenia, which can kill a litter of kittens in days.
Vaccines don’t make a cat bulletproof. But they make these diseases far less likely, and far less severe when they do happen. Here’s what each one is for, and when a cat should get it.
The short version
- Every cat needs the core vaccines: cat flu and panleukopenia.
- Rabies too, where the disease is found, the law asks for it, or the cat travels.
- Kittens start at around 8 to 9 weeks, with a second dose 3 to 4 weeks later.
- After the first booster, most grown cats need one every one to three years.
- A street cat going in for neutering can be vaccinated at the same time.
Core vaccines: every cat
Vets split vaccines into two groups. Core vaccines are for every cat, including cats that never go outside. Non-core vaccines are for cats whose life puts them at real risk. International Cat Care lists the core vaccines as:
- Feline panleukopenia, also called feline parvovirus or feline infectious enteritis. It causes severe vomiting and diarrhoea and is often fatal, especially in unvaccinated kittens. The virus can survive for years on the ground and on bowls and bedding, so an indoor cat can catch it from your shoes. The vaccine works very well.
- Feline herpesvirus and feline calicivirus, the two viruses behind most cat flu. They’re always given together. The vaccine doesn’t always stop a cat catching them, but it makes the illness much milder.
- Rabies, where the disease is present or the law requires it.
In many countries, the cat flu and panleukopenia vaccines come in one injection, so a kitten gets all three in one go.
Rabies: depends where you live
Rabies is more common in dogs, and dogs pass it to people far more often than cats do. But cats can catch it, usually from wild animals, and can pass it on. Where rabies is found, International Cat Care says cats should be vaccinated, and some countries make it the law. Our World Rabies Day story has more on the disease itself.
Rabies vaccination is also the key to travel. To move a cat between EU countries, the EU’s rules say it must:
- Be microchipped first. A rabies jab given before the chip doesn’t count.
- Be at least 12 weeks old for its first rabies vaccine.
- Wait at least 21 days after that first vaccine before travelling.
- Carry a European pet passport, issued by an authorised vet.
If a booster runs out, the next dose counts as a first one and the 21 days start again. Countries outside the EU have their own rules, so check before you book.
FeLV: for cats that go outside
Feline leukaemia virus (FeLV) weakens a cat’s defences against other illness, and most cats that stay infected die from it. It spreads through close contact: grooming each other, sharing bowls and litter trays, and fighting.
It’s a non-core vaccine, but International Cat Care says it can be very valuable for cats that go outside and meet cats they don’t know. The American feline vets’ 2020 guidelines go further and recommend it for every kitten and every cat under a year old, because young cats catch it most easily. Your vet will know how common it is where you live.
A few other non-core vaccines exist, against Chlamydia and Bordetella bacteria. Most cats don’t need them, though they can help in shelters and colonies with repeated outbreaks.
Kittens: when to start
Kittens get some protection from their mother’s milk, but it fades over the first weeks, and while it lasts it can also block a vaccine. That’s why kittens need several doses. International Cat Care describes a common schedule:
- 8 to 9 weeks: the first injection. In shelters and other high-risk places, vets may start earlier.
- 3 to 4 weeks later: the second.
- 16 to 20 weeks: a third, now often given, especially for panleukopenia.
- About a year later: the first booster. Some vets give it sooner, at around six months old.
Until it’s finished the kitten course, keep a kitten indoors and away from cats you don’t know. Not sure how old a kitten is? Our kitten age chart will help.
Grown cats: boosters
After that first booster, how often a cat needs another depends on the vaccine and on its life. International Cat Care says boosters may only be needed every one to three years. The American guidelines suggest every three years for the core vaccines in most adult cats, and every year for FeLV in cats at high risk.
A grown cat with no vaccine history, like most street cats, simply starts from scratch. Your vet will plan the doses.
Street cats: vaccinate at neutering
A street cat you’ve caught for neutering may never go in a carrier again. That makes the neutering visit the best chance it will get. Many trap, neuter and return programmes vaccinate cats while they’re under anaesthetic. Alley Cat Allies says TNR programmes are often the largest providers of rabies vaccines for cats in their area.
One dose isn’t a full course. But in a grown cat, the American guidelines say a single dose of some vaccines can be enough to protect it, and every vaccinated cat in a colony makes an outbreak less likely to spread.
Side effects
Serious reactions are very rare. For a day or two afterwards, a cat may be sleepy, eat a little less, or be sore where it was injected. Less often there’s vomiting, diarrhoea, limping, a temperature or a small lump at the injection site, usually on the scruff of the neck.
In fewer than one in 20,000 vaccines, a type of cancer called an injection-site sarcoma can grow where the needle went in. So keep an eye on the spot, and if a lump is still there after two to three weeks, or growing, see your vet straight away.
Questions people ask
Does an indoor cat need vaccines?
Yes, the core ones. Panleukopenia can survive for years on surfaces and come in on shoes and clothes, and cat flu viruses can travel on hands. Your vet may skip the non-core vaccines for a cat that never goes out.
When should a kitten have its first vaccine?
Usually at 8 to 9 weeks, with a second dose 3 to 4 weeks later and often a third at 16 to 20 weeks. Vets may start earlier where the risk is high.
Can a street cat be vaccinated when it’s neutered?
Yes, and it’s often the only chance. Many neutering programmes vaccinate street cats while they’re under anaesthetic. Ask the vet when you book.
This guide is general information, not veterinary advice. Which vaccines a cat needs depends on where it lives and how it lives, so ask your vet.
Snap the cats at your feeding spot, and you’ll always know which ones have been to the vet.
