Vaccinations in cats

Vaccinations are the most effective tool we have to prevent serious infectious diseases in cats. They prepare the body’s natural defences, so they can fight specific viruses and bacteria much more effectively, and with less damage suffered. Which vaccines your pet needs depends on their lifestyle and circumstances.

Although we only have effective vaccines against a few diseases, they have saved countless lives. Widespread use of vaccines has greatly reduced the number of cases of these diseases, but they are still around and case numbers quickly rise if vaccinations levels drop. Like any other intervention, vaccines can have side effects, but these are usually mild when compared to how devastating these diseases are. Place of living, lifestyle, contact with other animals and travelling plans should all be considered when deciding what vaccines to give.


What it’s for

What are vaccines for in cats?

We think of two categories of vaccinations in cats:

Core Vaccinations

These are some of the diseases cats are most commonly exposed to, but vaccines are very effective at protecting against them. They are very contagious between cats, and can also be caught from places frequented by other cats even without direct contact. You can read about core vaccines in the UK below or follow the links for more information.


  • Causes severe vomiting, bloody diarrhoea and suppresses the immune system
  • Very similar to Parvovirus in dogs but fortunately not as common
  • Vaccinated kittens and cats have mild to no symptoms

Rhinotracheitis Virus

  • Common cause of Cat Flu
  • Causes sneezing, runny nose and a fever
  • Can also cause conjunctivitis and other eye problems
  • Often hides in the body and causes bouts of disease later in life
  • Vaccination may not fully prevent re-infection but greatly reduces the symptoms


  • Common cause of Cat Flu, sharing many of the same symptoms as the one above
  • Calicivirus can cause high fever joint inflammation in young kittens
  • Vaccination may not fully prevent re-infection but greatly reduces the symptoms.

Optional vaccinations

These are for diseases that are either less common, less severe, less contagious, or are only a risk under certain circumstances. You can read about relevant ones in the UK below or follow the links for more information.

Feline Leukaemia 

  • Progresses slowly but eventually disrupts the functioning of the immune system and causes anaemia
  • Can promote the development of some types of cancer
  • Once settled in the infection cannot be eliminated, but vaccination allows the immune system to expel the virus before it fully sets in
  • This virus is quite fragile out in the environment, and indoor cats are at low risk. It’s much more common in some areas


  • No cases of Rabies transmission have been reported in the UK for many decades, and cats are naturally fairly resistant to infection, so this vaccine is only recommended when travelling abroad
  • Rabies is still occasionally detected in Europe and common in other continents
  • Vaccines are very effective at preventing it


  • Bacteria that causes nasty bouts of conjunctivitis, especially in very young kittens
  • Can lead to blindness in newborns
  • Very contagious between animals in close contact but doesn’t travel well
  • Vaccination is recommended for multi-cat households where it has been known to cause issues

Other vaccines are available, but are either not effective enough to justify widespread use or are only necessary in very specific situations.


How it’s done

How do vaccines work?

  • Vaccines give our body a chance to get a practice run against a harmless version of an infectious agent.
  • A killed or weakened infectious agent is administered into the body
  • The body learns to prepare defences quickly if the real thing comes along
  • In some cases this completely blocks a disease from entering the body, in others it reduces the symptoms and speeds up recovery.
  • The stored defences tend to become less active over time, so regularly getting more practice in helps the response stay strong and effective. For this reason, boosters may be recommended regularly.



How much do vaccines cost?

Vaccines are difficult and expensive to produce, but the widespread use of the common ones allows their final cost to be within the affordable range. What is included in the price of vaccination:

  • A health check: a vet has to make sure the animal is in good health. This is to reduce the chance of side effects and make sure the animal’s immune system is up for the task (otherwise the vaccine may not work).
  • The consultation fee: accounting for the vet’s time and expertise. The consultation cost depends on area and type of practice, among other factors.



What are the risks of vaccinations?

Vaccinations are one of the most common and safe treatments in medicine, but any intervention has the potential for complications. The following side effects are commonly discussed:

Most common side effects of vaccinations

  • Mild reactions
    • Fever
    • Lethargy (being quiet and not themselves)
    • Soreness or swelling at the injection site

Last 1-2 days after vaccination

Cause: the immune system being hard at work


  • Monitoring
  • Anti-inflammatories

Rare side effects

Allergic reactions to vaccines

These happen once in any 10000 vaccinations given.

  • Anaphylactic reactions:
    • Severe
    • Happens within minutes of the vaccine being given. Symptoms include:
      • Collapse
      • Struggling to breath
    • Tip: Stay near the vet practice for 10-20 minutes after your cat gets a new vaccine.
  • Delayed allergic reactions:
    •  Swelling, crusts and sores around the face
    • Puffy eyes, hives and intense itching.
    • Discuss with a vet
  • Injection site sarcoma
    • Very rare (1 per 10000-30000 vaccinations) but
    • Can be very difficult to treat and even fatal
    • If a post-vaccination swelling is still present after 3-6 weeks, or becomes bigger than a grape, testing should be done as soon as possible.

Vaccine inefficacy

  • Causes:
    • Your cat being unwell at the time the vaccine was given
    • Genetics
    • Presence of maternal antibodies in kittens younger than 8 weeks
  • Risks:
    • The animal may then be unknowingly exposed to disease, believing it is protected.
  • What to do:
    • Blood tests to check the levels of antibodies
    • Some countries request a blood test to confirm the Rabies vaccine has been effective before allowing a pet in


Recovery tips

Recovery Tips after vaccination in cats

  • Most cats will be a bit stressed after a vaccine, it is good to keep an eye on them for a few hours while also giving them a chance to settle and relax. Pheromone sprays or catnip may help a lot.
  • If appetite isn’t great, it’s fair enough to entice them with their favourite food to help them recover.

Help is available in the Joii app if you would like to discuss this further.


When to worry

When to worry after a vaccination

Seek help from a vet immediately if your cat develops:

  • Weakness
  • Disorientation
  • Fainting
  • Laboured breathing
  • Severe itching and swelling of the face
  • Severe vomiting or diarrhoea

Call a vet straight away if your cat develops:

  • Sores/crusts on their skin
  • Puffy eyes and/or lips
  • Itchiness
  • Lethargy

Speak to an online vet in the Joii app or call your vet for an appointment if:

  • Swelling is still present after 3-6 weeks
  • Your pet is still acting out of character or eating poorly after 2-3 days
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