Cat Vaccination Myths and Misunderstandings

That you’ve just adopted depends on you to keep them happy and healthy, which means providing a cat-friendly home, a , and lots of love. Another vital aspect of this care is vaccination. However, it’s not unusual for cat guardians to misunderstand which cats need which and when, plus what protection vaccination offers. So, let’s explore some common myths and misunderstandings to set the record straight about cat vaccination.

Myth: Kitten vaccines protect for life

kitten receiving vaccination
(Photo Credit: Dina Damotseva / Getty Images)

There is a widely held misunderstanding that vaccinating a kitten gives them immunity for life. This is false. Many perfectly well-meaning don’t get their cats booster shots because they don’t realize immunity wanes with time.

Booster shots are important to maintain the cat’s protection against disease. We know this by looking at blood antibody titers, which show levels fall over time to the point where they are no longer detectable.

Once this happens, if the cat encounters infection, they are potentially at risk because the immune system may no longer remember how to fight against the bug.

How long a cat remains protected varies between individuals, and there are many variable factors that influence this. So rather than put the cat through blood tests each year, manufacturers did a lot of research to check out the average protection time and when a booster dose is needed.

It is this data that the vet uses when advising a cat parent that their cat needs another shot.

Myth: Older cats no longer need vaccination

Your has been vaccinated all their life. Surely, in their old age, they have built up enough immunity to skip the booster?

Actually, no. While this is a logical argument, sadly this isn’t the case.

Firstly, even with a healthy, strong immune system, the protection drops over time and needs “boosting.”

Secondly, older animals have weaker immune systems. This means they are less able to fight infections and depend more on vaccine protection, rather than less. Thus, it becomes more important, not less, for seniors to get their booster shot.

Myth: Indoor cats don’t need to be vaccinated

Wrong! (Well, mostly.)

Some of the nastier viruses, such as , are equivalent to a super-villain in terms of toughness. They can survive on sidewalks in all weathers for long periods of time. If you walk on the virus, you can bring it indoors on your shoes, so not even indoor cats are safe.

Therein lies the crunch. An is at low risk but not no risk. However, will risk asses the cat and may opt out of vaccinating against conditions that require close contact to spread, such as feline leukemia virus.

Myth: We over-vaccinate cats

Many people worry about over-vaccination in pets. It’s a concern veterinarians take very seriously. This is why vets avoid unnecessary vaccinations by adapting vaccine protocols to meet each individual cat’s risk factor and how long immunity lasts to a particular virus.

To do this, vets divide the vaccine components into core and non-core. This simply means essential and non-essential. For example, vaccination against rabies is core, whereas protection against feline leukemia virus is non-core for an indoor cat.

In terms of how often to repeat a dose with a booster shot, this is decided by how long protection lasts. For example, protection against feline leukemia lasts one year, and requires a yearly booster, while protection against cat flu lasts for three years.

Myth: Vaccines do more harm than good

female veterinarian giving cat a vaccination
(Photo Credit: FatCamera / Getty Images)

Every responsible cat parent should make an informed decision about what’s best for their pet as an individual. However, when weighing up the pros and cons of vaccination, it’s relevant to know the benefits far outweigh the risks.

Diseases such as cat flu, distemper, and feline are still out there and have life-changing consequences. Balance this against the risks of vaccination which can be divided into common-but-mild reactions and rare-but-serious, as outlined below.


After a vaccine, around one in 10 cats experience a soft swelling at the injection site. This is a temporary lump that goes away after a couple of weeks and nothing to worry about.


This reaction mainly affects young kittens, usually at their first vaccination. It’s thought to be due to the Calici virus ingredient — part of cat flu — and the immune system registering the vaccine.

Affected kittens may run a mild fever, limp, and go off their food. The effect lasts for two to three days and then resolves of its own accord.

It is usually a one-off event and doesn’t recur with subsequent vaccines.

Feline Injection Site Sarcomas (FISS)

There is no denying these injection-related tumors are serious. Studies show that this is a rare complication of injection, affecting approximately one to four in every 100,000 cats.

Since vaccines are one of the most frequently administered injections, FISS has become linked to vaccination — but can occasionally occur with other injections, such as long-acting antibiotics or steroids.

To reduce this risk, vets take care to tailor vaccine protocols to the individual to reduce unnecessary vaccinations. They also give vaccines in an extremity, such as a back leg, and each year record where the injection was placed, so any suspicious swelling can be linked back to the injection and monitored.

When all’s said and done, it’s up to each cat parent to make an informed decision about what’s best for their pet. But just be sure to base that decision on the facts, rather than fiction, of cat vaccinations.

Leave a Reply

Your email address will not be published. Required fields are marked *