Vaccinations for your Cat

Which diseases do we vaccinate against?


Feline herpesvirus and calicivirus are responsible for the majority of cases of cat flu. Clinical signs include fever and lack of appetite, respiratory tract problems such as sneezing, nasal discharge, coughing and even pneumonia, eye problems, mouth ulcers and, rarely, skin or joint involvement. In kittens or elderly cats or cats with other health problems the disease can be fatal. Although most patients survive, cat flu frequently becomes chronic leading to recurrent bouts of the disease. Additionally, cats can continue to spread the virus and thereby infect other cats.


This virus causes a severe and often fatal disease characterised by severe vomiting and diarrhoea and damage to the immune system. In cats which do survive, recovery is often very slow. When young or unborn kittens are infected permanent brain damage is usually seen. The virus itself is very resistant and can survive for several months in the environment – it can therefore be transmitted without direct contact between cats.


Infection with the feline leukaemia virus frequently leads to lifelong infection. Such cats will carry the virus sometimes for several years without showing any sign of disease. Ultimately, chronically infected cats will unfortunately develop fatal disease. Despite the name of the virus, infection does not necessarily lead to leukaemia, but more often to a variety of diseases resulting from failure of the immune system. Such problems as secondary infections, anaemia or tumours are generally not controllable in the end stages of the disease, which ultimately leads to death or the need for euthanasia.

Feline leukaemia virus can only be transmitted through contact with another cat, so indoor cats which it is certain will have no contact with outdoor cats do not need this vaccination. However, it is only necessary for an unvaccinated cat to go outside once and have a fight or some form of contact with another cat to pick up the virus.


Kittens generally need two vaccinations given three weeks apart (depending on the vaccine used). The first vaccination is usually given when the kitten is about nine weeks old. Full protection starts about seven to ten days after the second vaccination has been given.

The two vaccinations are given to ensure a good immune response resulting in strong protection against the diseases mentioned. It also makes sure that maternal antibodies (antibodies received by the kitten from the mother’s first milk) do not stop the vaccination working. The maternal antibodies give the kitten some protection during the first few weeks of life until its immune system has matured, but unfortunately they interfere with the response to vaccination. The maternal antibody levels usually start to drop after six weeks and disappear when the kitten is between eight to ten weeks of age, leaving the kitten open to infection. Giving two vaccination injections helps to catch the kitten at the times when it begins to need protection and can respond to the vaccine.


The basic answer is that a cat should be vaccinated again when the level of protection starts to wear off. This can be an individual time period for each cat and also depends on the type of vaccine used. Currently the vaccine manufacturers advise that we vaccinate yearly to ensure that the level of protection stays high. There is some evidence that immunity may last longer in individual cats, but to date we do not know how often that happens and for how long protection may last. Blood tests can be used in dogs to determine antibody levels but this does not seem to be a reliable method of determining immunity levels in cats.


An annual health check plays a vital role in the process of vaccination. Because successful vaccination is only possible when the body is able to build up a sufficiently strong immunity against the diseases, it is important that the cat is healthy at the time of vaccination and that the immune system is working properly and is not ‘otherwise engaged’. The health check prior to vaccinating your cat makes sure this is the case. If we find cause for concern, we will not vaccinate your cat, but treat the problem we find or – if we cannot make a diagnosis through a clinical examination, we will advise further tests to find out what is going on. Only after we have sorted out the problem will we ask you to come again to have your cat vaccinated.

The annual health check itself is just as important as regular vaccination, as this allows us to spot problems early and to give assistance with routine healthcare issues – after all, our patients cannot tell us if there is something bothering them!


Vaccination is a medical procedure and even though it looks easy, only people with a qualification in veterinary medicine are allowed to vaccinate animals. These days vaccination is a very safe procedure and problems are only rarely encountered. Unusual reactions of the immune system (‘vaccine reactions’) are only rarely reported and the risk of encountering one of the diseases is far greater than the risk of a reaction to the vaccine. Occasionally a small skin lump appears at the site of the vaccination, but this usually disappears within a few days. In very rare cases cats are unable to produce a proper vaccine response even when they are healthy.


We strongly recommend regular vaccination as unfortunately we still not infrequently treat cats with the diseases mentioned above. The outcome of these infections can be very serious or fatal and can be avoided by regular vaccination.