Vaccinating your cat

Keeping your cats safe from infectious disease is an important part of responsible cat ownership.  Many cats we take in for rehoming have not had their vaccinations kept up to date as their owners were unaware of the need for boosters.  This post will cover the main points about vaccinating, with sources of extra information listed at the end. 

Pepper is a herpesvirus carrier with a
persistent eye ulcer
Source: author

Why should we vaccinate cats?
The reason for vaccinating is due to the potentially fatal prognosis for any cats who suffer from these diseases. If not fatal, the viruses often have long term effects on the cat, who will be a lifelong "carrier" of the virus.  For example, herpesvirus can cause painful eye conditions including ulcers. 

What is a vaccine?
A vaccine is a liquid suspension containing part of a virus or bacteria which triggers an immune response when given to the cat. The micro-organism in the vaccine has been altered in such a way to stop it causing disease but allows the cat to develop immunity to the disease without suffering from it.



How do they work?
The initial vaccine is given as two doses under the skin.  When the immune system is exposed to the altered micro-organisms the immune system recognises them as foreign and makes antibodies against them.  White "memory" cells are also generated by the immune system, which will be able to quickly reproduce these antibodies in the future when it is exposed to the disease-causing forms of the viruses. Future vaccinations, known as boosters, will boost the memory of the immune system by reminding the white blood cells of the antibodies necessary to fight these diseases. 

What are the vaccinations for?
All our foster cats receive vaccinations against the main diseases "RCP" and also FeLV:

Image source: author

Other vaccinations are available for:
Chlamydophila felis - bacteria causing painful conjunctivitis with discharge and redness of the eyes, but it can also be a cause of cat flu.

Bordetella bronchiseptica - bacteria causing flu-like signs such as sneezing, runny nose and eyes, high temperature and a cough. It can cause pneumonia and sudden death in kittens. The same bacteria cause kennel cough in dogs. 

Rabies - a lethal virus which is not currently a problem in the UK but cats travelling abroad under the Pet Travel Scheme must have vaccinations against rabies.

What are the benefits of vaccination?

Vaccines help to:

• Reduce symptoms of diseases caused by viruses
• Reduce the level of calicivirus shed by a cat (to potentially infect other cats) for up to one year after vaccination 
• Prevent death from panleucopenia
• Prevent FeLV from remaining in the blood 

When should we vaccinate our cats?
The first vaccine is given at 8-9 weeks of age, with the second injection 3-4 weeks later.  Current vets advise cats should be revaccinated against all components one year after the first vaccination course and then every year for leukaemia, and every three years for rhinotracheitis, calicivirosis and panleucopenia. Below I will mention the independent guidelines on vaccination protocols. 

Purevax RCP FeLV used for Cats
Protection foster cats
Source: https://shop.agrihealth.ie/

What about risks and adverse reactions?
Some cats may experience a mild reaction following a vaccination: this is normal as it shows the cat is having an immune response. Signs may include:

• Lacking energy / lethargy
• Poor appetite
• Tenderness at the injection site for around 24-48 hours after vaccination 

Other side effects that can occur include a high temperature, vomiting and diarrhoea, lameness and flu-like signs but these side effects are more likely to occur if the cat has already picked up another infection at time of vaccination – the immune system is then under too much stress to cope with everything.  Occasionally, a lump may occur at the site of injection and in very rare cases, cancers may develop in the same spot. 

Vaccination failure is rare but may result from storage issues, incorrect administration, failure of the cat's immune system to effectively respond if already compromised, the virus taking hold before the vaccination is given, or subsequent infection occurring from a strain of microorganism that was not included in the vaccine.  Vaccination failures and severe reactions to vaccines are very rare and the benefits of vaccinating far outweigh the risks involved. 

The Veterinary Medicines Directorate (VMD) run a surveillance scheme where members of the public and veterinary surgeons in the UK can voluntarily report any suspected adverse reactions (SARs) to veterinary licensed drugs, including vaccines. 

Veterinary Medicines Directorate Suspected Adverse Reaction reporting website
www.vmd.defra.gov.uk/adversereactionreporting/

The number of SARs reported after vaccination are very low in comparison with the thousands of cats suffering from infectious disease.

For more information check out the links below or book an appointment with your veterinary surgeon.  

So what's the latest advice?*

The WSAVA Vaccination Guideline Group and the European Advisory Board on Cat Diseases (ABCD) are independent bodies that maintain up to date guidelines on vaccinations for cats. Both bodies advise we should:

• Aim to vaccinate more individual cats
• Aim to vaccinate each individual cat less often and only with antigens that are necessary for that individual cat

Not vaccinating enough leaves the animal at risk of developing an infection and lowers overall immunity levels in the population. Over-vaccinating results in costs for owners and increases the risk for adverse reactions. 

To help make a decision we can consider the individual situation of each cat by assessing:

• The risk of contracting infections - indoor or outdoor cat? Single cat or multicat household?  Some vaccinated cats in the household may shed a virus without showing symptoms.  Exposure to other cats at boarding catteries, shows or vet practices?
• The risk of a significant infection developing - this is higher in kittens younger than 4 months of age and also in senior cats. The general health of the cat may have an impact and whether there are other stressors present such as poor nutrition or a parasite burden. 
• The likely severity of the disease in question - considering the nature of the disease and age/health of the cat
• Potential for spread of the disease - is the cat in a multicat household, does the cat visit a boarding cattery or cat shows
• potential adverse effects following vaccine administration - mild disease, allergic reaction, vaccine-related lumps or cancers

Martha Cannon summarised the international recommendations from the WSAVA and the ABCD on vaccination in cats in her lecture at the ISFM Feline Symposium for Nurses in Birmingham April 2019.  They reiterate that panleukopenia, herpesvirus and calicivirus are core vaccines to be given to all cats, with leukaemia being a non-core vaccine advised for cats with access to outdoors and make recommendations depending on different risk levels. 

Always consult your veterinary surgeon to discuss concerns regarding vaccinations and to make a tailored plan for your cat dependent on their risk level. 

References:

European Medicines Agency: Purevax RCP FeLV

Cats Protection Veterinary Guide on Infectious Disease and Vaccination

International Cat Care:  Vaccinating your cat

*Final section added following the ISFM Feline Symposium for Nurses in April 2019, vaccination lecture given my Martha Cannon, which was then published in ISFM's Feline Focus April 2020.  

WSAVA Vaccination Guidelines