Vaccination in Cats

Regular vaccination is an important part of routine health care for your cat and helps to ensure your cat remains fit and well. Many serious and life-threatening diseases can be prevented by vaccination. In Australia, there are a number of vaccines that are currently available for use in cats to protect against the following diseases:-

Feline Herpes Virus Type 1 (FHV-1; feline rhinotracheitis virus)
Feline Calicivirus ( FCV)
Feline Panleukopenia (feline infectious enteritis; feline parvovirus)
Feline Chlamydial Infection
Feline Leukaemia Virus ( FeLV)
Feline Immunodeficiency Virus (FIV)

How do vaccines work?

Vaccines work by exposing the body's immune system to a particular modified infectious agent.  This causes the white blood cells to react to fight the infection by producing proteins (antibodies) which are able to bind to and neutralise the infectious agent (antigen).  Antibodies work together with other white blood cells (lymphocytes) which are able to identify and kill cells within the body which have become infected by the agent (cell mediated response).  After vaccine exposure, the body 'remembers' the particular antigens so that when they are encountered again it can mount a very rapid and strong immune response preventing the cat from showing clinical signs of disease.  It is important to realise that most vaccines work by preventing your cat from becoming ill and may not prevent it from becoming infected.  This means that if a vaccinated cat becomes infected with ‘cat flu’ it may still shed the disease producing organism which can infect unvaccinated animals which will then become ill.  This is not a major consideration in the pet cat but may be important in the breeding colony.

What is the difference between the various types of vaccine?

The 2 major types of vaccines for use in cats are

Modified live vaccines- these vaccines contain live organisms that are weakened (attenuated) so that they do not produce disease but will multiply in the cat's body. It is not advisable to use modified live vaccines in pregnant queens or cats whose immune system is not working properly e.g. cats infected by feline immunodeficiency virus (FIV).

Killed (inactivated) vaccines - these vaccines are prepared using fully virulent organisms that have been killed by chemicals, UV light or radiation.  Because, on their own, they do not give such a high level of protection, a chemical (adjuvant) is added to the vaccine to stimulate a better immune response.


When should my kitten be vaccinated?

Kittens should be first vaccinated at 6 to 8 weeks and then every 4 weeks until they are 16 weeks or older. For most kittens this will mean 3 vaccinations. A kitten will not be fully protected until 7-10 days after the last vaccination.  Under specific circumstances we may advise an alternative regime.

How often should booster vaccinations be given?

Guidelines for booster vaccinations are constantly being debated around the world. Vaccines currently used in Australia are labelled by the manufacturer to be given every 12 months. We support this and recommend that after the initial series of kitten vaccinations that cats be vaccinated every 12 months.

Will vaccination always protect my cat?

Vaccination will protect the vast majority of cats but under some circumstance vaccine breakdowns will occur.  There are many reasons for this including:-

1.       Variations between different strains of viruses - this is particularly true of FCV where many different strains exist, not all of which are covered by the vaccines available.

2.       Maternally derived antibodies - when a kitten is born it is protected in its early life by antibodies passed from the queen in the first milk (colostrum).  These antibodies can also prevent vaccination from working properly. The amount of colostral antibodies that each kitten receives is variable and so the age at which a kitten can respond to vaccination successfully will also vary.  This is part of the reason why two or three injections are given in the primary course.

3.       The cat was not healthy at the time of vaccination - 'stress' can prevent a good response to vaccination.  For this reason your vet will give your cat a physical examination before a vaccination is given.

4.       The cat may also be pre-infected with the ‘cat flu’ virus and incubating the disease.

If you feel your cat has contracted an infection for which it is vaccinated then let your veterinary surgeon know.  Investigation to establish why vaccination has possibly failed can be undertaken.

What are the risks of vaccination?

Generally the risks of vaccination are extremely low.  Severe reactions being very rare.  Many cats experience mild reactions at the site of vaccination where a lump may occur that can be painful.  Generalised reactions are sometimes seen, the cat being quiet, lame and often off its food for 24 hours after vaccination.  Occasionally more severe signs occur including vomiting, diarrhoea and profound depression.  Under these circumstances your veterinary practice should be informed.  Vaccine reactions appear to occur more commonly in kittens and some purebred cats.

Which are the most important vaccinations to have?

We suggest all cats be vaccinated against feline herpes virus, feline calicivirus and feline panleukopaenia. This is often referred to as a F3 vaccination.
For outdoor cats, we recommend vaccination against feline immunodeficiency virus (FIV).

Feline respiratory virus infection
Disease is caused by feline herpes virus or feline calicivirus and is commonly termed 'cat flu'.  It is a common disease in unvaccinated cats and can cause long-term problems, including chronic sneezing, nasal discharge, inflamed eyes and severe gum problems.

Feline panleukopenia infection
This is now an uncommon disease that causes a severe and often fatal gastro-enteritis.  Vaccination provides a high level of long lasting protection.

Feline immunodeficiency virus infection
All outdoor cats are susceptible to infection with FIV if bitten by an infected cat unless        protected by vaccination against the virus. The initial vaccination is followed up by 2       more vaccinations 2-4 weeks apart and then with annual boosters. FIV vaccines can be          given at the same time as regular F3 vaccinations.

Feline Chlamydial infection
This tends to be a particular problem in colony cats. Chlamydial infection causes a painful inflammation and swelling of the conjunctiva (the membrane around the eye) and has been associated with infertility in queens. This vaccine can make many cats sick for several weeks and only suggest vaccination in certain circumstances.

Feline leukaemia virus infection
FeLV causes suppression of the immune system, cancer of the white bloods cells and          solid tumors. It is an extremely rare disease in Australia seen mainly in colonies. We    only suggest vaccination for FeLV for at-risk cats.

Regular vaccination is an important part of routine health care for your cat and helps to ensure your cat remains fit and well.