As the current economic situation continues to squeeze the family finances, I have noticed an increase in clients who would prefer not to vaccinate their cat. There are probably many more who are simply not showing up for their yearly exam so we don’t even have a chance to discuss the issue with them. Now, there are certainly times when I would accept that a cat should not be vaccinated, and in fact I often have to convince my clients NOT to vaccinate their pet if they are ill in any way. Vaccines are part of a preventative medicine protocol, and should in most cases only be given to healthy pets when the benefit of having the vaccine on board outweighs the risk of giving it. In most cases, however, the benefit far outweighs the risk, and therefore responsible vaccination is highly recommended. I’ll discuss what ‘responsible’ vaccination means in greater detail in my next blog, but first I thought I might explain a bit more about why vaccination is so important.

What diseases are cats routinely vaccinated against?

Feline vaccinations are generally separated into ‘core’ (those that every cat should have) and ‘non-core’ (those that only high-risk cats should receive). The four core vaccines that should be given to every cat are parvovirus, herpesvirus, calicivirus, and rabies. The rabies vaccine, however, should only be given in areas where rabies is a concern (for example, in the United States). The UK is currently rabies-free, therefore British cats are not routinely given the rabies vaccine unless they will be travelling to other countries. If you would like more information about the rabies vaccine, please speak with your vet. There may very well come a day when we are also required to vaccinate for rabies in the UK, but for now I’ll concentrate on the first three diseases.


• The feline parvovirus is the name of the virus that causes feline panleukopenia. This is such a widespread disease that it has many other names, including feline infectious enteritis, feline distemper, and cat plague. Symptoms include severe vomiting and sometimes bloody diarrhoea, ataxia (loss of balance or stumbling), and death with a mortality rate of more than 50% in kittens under 1 year of age and 10% in cats older than 1 year. It can also cause abortion or defects of unborn kittens if the mother cat is infected during pregnancy (pregnant cats should also not receive certain types of the vaccine for the same reason). The feline parvovirus should not be confused with the canine parvovirus. Some strains of canine parvovirus could potentially affect cats, but those that have received the feline parvovirus vaccine should be covered. Likewise, the feline version has not been shown to infect dogs.


• The feline herpesvirus is what causes feline viral rhinotracheitis, otherwise known as feline influenza (cat flu) and feline coryza. It is responsible for about half of the respiratory disease seen in cats and along with calicivirus and a few other nasty bugs and environmental factors, leads to the disease called ‘feline respiratory disease complex’. In most cases, herpesvirus infection results in mild symptoms that go away on their own (like sneezing or mild nasal discharge) however it can cause severe rhinitis (inflammation in the nose and sinuses), conjunctivitis (eye infection), fever, depression, and loss of appetite as well, with kittens less than 6 months old showing the most severe symptoms. It can be particularly bad in multi-cat households, catteries and shelters, with a mortality rate of up to 20-30%. Like parvovirus, it can cause abortion in newly-infected mother cats. Unlike parvovirus however this vaccination does not prevent cats from getting this disease, but it does lessen the severity of symptoms making it less likely to be fatal or develop into pneumonia. The virus can live in the body for long periods of time and become reactivated during times of stress (such as boarding at the cattery, moving house, new pets in the house or pregnancy) or underlying medical conditions (treatment with steroids or concurrent FeLV or FIV infection), which is why even vaccinated cats will sometimes ‘catch a cold’ when they are stressed.


• Like herpesvirus, feline calicivirus also leads to the condition called feline respiratory disease complex and is responsible for most of the other 50% of cases. The symptoms of calicivirus are similar to those of herpesvirus, with sneezing, nasal discharge, conjunctivitis, fever and loss of appetite however severe infections result in significant eye disease (sometimes so swollen that the eye cannot be opened) and ulceration of the mouth and tongue. It is fatal in up to 20-30% of cases, particularly young kittens. Like herpesvirus, vaccination does not prevent infection but will make the disease easier to bear and less likely to cause long-term or fatal complications.

A note about Feline Leukaemia (FeLV) and other available vaccinations

• There is one other vaccine that is recommended for most cats in the UK but is less widely used in the US, and that is FeLV or feline leukaemia virus. The reason for this is that most American cats are kept inside for their whole lives while British cats are allowed outdoors where they are more likely to contact other cats. FeLV is a retrovirus that is spread by the saliva of infected cats in close contact or from mother to kitten. The prevalence of this disease is currently thought to be about 1% in healthy UK cats (nearly 20% in sick cats), but in reality could be either higher or lower. The virus itself causes a cancer of the blood cells called leukaemia and this is usually fatal. The chance of picking up FeLV is much greater in kittens than it is in cats over 1 year old, although older cats can certainly become infected. As this is considered a non-core vaccine, its use is slightly less straightforward than the previous three vaccines, but most UK vets do currently recommend it.

• Other vaccines available for cats include chlamydophila and bordetella (recommended for use in specific situations), and FIV and FIP (which although they do exist, are not recommended for any cat). Unless you are a breeder or shelter manager, you will probably never be offered one of these vaccines. If you are, make sure you understand why the vaccine is being recommended and feel free to discuss your concerns with your vet.

Feline parvovirus, herpesvirus, calicivirus, rabies and leukaemia virus are all serious illnesses that can be severely debilitating if not fatal to your cat. Vaccination, although not a complete guarantee against infection, is highly effective in preventing and limiting these diseases. I’ll discuss other aspects of vaccine administration in my next article, but clearly the concept of vaccination is a sound one and we should be making the most of this invaluable tool in preventative medicine. Not having your pet vaccinated is like placing a bet on their health. Would you being willing to bet your pet’s life on the spin of a roulette wheel? Not having them vaccinated (although admittedly the odds are much lower) is no different. And of course, for those sceptical souls with a more financial outlook on the whole subject, I’d like to point out that the cost of the vaccine is significantly lower than the cost of treating any of these diseases!