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VACCINATION IN CATS Recent
advances in medical science have resulted in an increase in the number and type
of vaccines that are available for use in cats. Currently cats can be vaccinated against six different
diseases:- Feline
panleukopenia (= feline infectious enteritis; feline parvovirus)
Feline herpes virus type 1 (= FHV-1; feline rhinotracheitis virus)
Feline calicivirus (= FCV)
Feline chlamydial infection
Feline leukaemia virus (= FeLV)
Rabies (Rabies
vaccine is, however, reserved for those cats that are travelling abroad or have
entered the UK from abroad.) Attempts
are being made to produce vaccines against other infectious diseases in cats,
some are already available in other countries e.g. an intranasal vaccine against
feline infectious peritonitis (FIP). How do vaccines work?
Vaccines
work by exposing the body's immune system to a particular 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
vaccinal 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 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?
Three
major types of vaccine are produced for use in cats. 1.
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. Live
vaccines are generally considered to cause a stronger, longer lasting immunity
than inactivated vaccines. 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). 2.
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. 3.
Subunit vaccines -
these are dead vaccines in which the infectious organism has been broken apart
and only certain parts are included in the vaccine.
In some cases this is achieved by using genetic engineering techniques. When should my kitten be vaccinated?
Generally
kittens are vaccinated for the first time at between 8 and 10 weeks and a second
dose given at 12 weeks. A kitten
will not be fully protected until 7-10 days after the second vaccination.
Under specific circumstances your veterinary surgeon may advise an
alternative regime. How often should booster vaccinations be
given?
Booster
vaccination is generally carried out yearly.
Some panleukopenia vaccines can be given once every two years.
All cats should be boosted regularly, adult cats are also susceptible to
these infections particularly as they grow old and their immune system becomes
less efficient. Will vaccination always protect my cat?
Vaccination
will protect the vast majority of cats but under some circumstances vaccine
breakdowns will occur. There are
many reasons for this including:- 1.
Variations between different strains of viruses - this is particularly
true of FCV infection which has a large number of different strains 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 will also prevent vaccination from working properly. The
amount of colostral antibodies that each kitten receives is variable hence the
age at which a kitten can be vaccinated will also vary.
This is part of the reason that two 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 it is better to let a kitten settle in its new home for 5-7 days
before a vaccination is given. If
you feel your cat has contracted an infection for which it is vaccinated then
let your veterinary surgeon know so any tests to try and establish why
vaccination has failed to be protective can be undertaken. What are the risks of vaccination?
Your
veterinary surgeon will be able to advise you. Which are the most important vaccinations to
have?
This
is a difficult question and will depend on individual circumstances including
the area you live in and the lifestyle of your cat. Your veterinary surgeon will be able to advise you of the
most appropriate vaccinations to give your cat. Feline panleukopenia infection
This
is an uncommon disease that causes a severe and often fatal
gastroenteritis. Vaccination
provides a high level of long lasting protection. Feline respiratory virus infection
Disease
is caused by FHV-1 or FCV and is commonly termed 'cat flu' whilst not usually
very serious it is a common disease in unvaccinated cats and can cause long-term
problems. Vaccination is less
effective as immunity is not long lived. Cats
at high risk may needed to be vaccinated twice yearly to provide better
protection. Feline Chlamydial infection
This
tends to be a particular problem in colony cats. Chlamydiosis is a bacterial infection causing a painful
inflammation and swelling of the conjunctiva (the membrane around the eye) and
has been associated with infertility in queens. Infection in colonies of cats can last for long periods as
protection against reinfection is relatively short lived.
Vaccination can help to prevent infection becoming established in a
colony and can be used in conjunction with treatment where infection is already
present. Feline leukaemia virus infection
Whilst the majority of cats are able to combat this infection a significant proportion (about 30%) will become persistently infected by the virus. The vast majority of persistently infected cats will die from tumours or due to the immunosuppression caused by the virus. Current vaccines provide a good level of protection and do not interfere with routine testing for the virus in breeding colonies. Because the virus tends to take many months before it causes disease infected cats can appear completely normal. For this reason your veterinary surgeon may suggest that your cat has a blood test to make sure it is not infected before vaccination. Despite vaccination a few cats will still become infected with the virus. REGULAR VACCINATION IS AN IMPORTANT PART OF ROUTINE HEALTH CARE FOR YOUR CAT AND HELPS TO ENSURE YOUR CAT REMAINS FIT AND WELL. |