Feline Leukaemia Virus. It also seems to create more confusion in peoples' minds than any other! This article highlights the major facts about Feline Leukaemia Virus (known as FeLV) that affect all cat owners.
You're right. Leukaemia and other cancers normally are one-off events that affect an individual only.
(See the section on cancers below.) But cats can get cancers as a result of
being infected by Feline Leukaemia Virus. It's not the cancers that are infectious, but the virus that causes
It's a virus that affects only cats. It got its name because it can cause Leukaemia (see the
glossary below), but in fact the virus can cause many other different diseases too.
They get it from close contact with other cats that are infected.
It is impossible to tell without a blood test. The virus can be present for a long time before a cat shows any
symptoms, so an apparently healthy cat is not necessarily free of infection.
The virus will start to multiply in your cat. Fortunately most cats then make antibodies to the virus and
reject the infection. But about 30% of cats - especially younger ones - cannot reject FeLV and they
become permanently infected. These cats shed FeLV and are the source of infection for other cats.
The virus keeps on multiplying inside them until it damages their white blood cells (see the glossary below). When this happens the cat can get infections that it would normally fight off easily. These infections eventually kill the cat. Most permanently infected cats die within three years or so of becoming infected.
Sometimes the virus causes cancer of the white blood cells before it has caused other major damage.
These cats die of the cancer.
The only way to tell is by doing a blood test. The symptoms in infected cats are so variable that they are
not a reliable way of identifying FeLV infection. But if your vet finds signs like a fever that won't go away, or
persistent infections of the eyes, nose or mouth then a blood test may be recommended to see if FeLV
could be the cause.
Unfortunately there is nothing we can do to halt the FeLV infection. We can help to treat some of the
symptoms, but infected cats usually die quite soon after symptoms are seen. Very often the kindest
thing is to put affected cats to sleep rather than prolong suffering.
There are two ways:
Uncomfortably common. Estimates vary between 1% and 10% of UK cat deaths being due to FeLV. The
variation in these figures is because the true incidence is quite hard to measure.
As shown above, FeLV is unlike most other infections. This has commonly led to people misunderstanding
the disease, which in turn results in inaccurate 'facts' being reported about FeLV. These cause a lot of
confusion. The only way to be absolutely sure that what you are hearing is true is by checking with a vet
who deals daily with cats.
|Cancer is a disease where a part of the body starts to grow wrongly.|
In healthy animals cells (see the glossary below) divide often to replace ones that are worn out or lost. For example some of our white blood cells only last a day, and those lining our intestines are worn away after only four days.
The genes (genetic code) of each cell decide how much it needs to divide, and when it must NOT divide.
If the genes are damaged a cell may start to divide non-stop. More and more of that type of cell are made. They may also spread to other areas of the body. This is cancer. Animals die of cancer when the cancer cells have damaged too many of the normal cells, which then stop working.
|Causes of cancer|
Antibodies: special proteins that the body makes to target and attack specific infections.
Cells: All animals are made of tiny building blocks called cells. Each type of cell
has a different job. e.g. brain cells store messages and white blood cells attack bacteria and viruses.
Genes: These are the 'computers' that control the behaviour of cells. They dictate
whether cells will grow or divide, or even whether they will become a heart cell, a white blood cell or some
other sort of cell.
Leukaemia: cancer of the white blood cells. In people
and dogs this is usually NOT caused by viruses. Cats are a special case because only they can get FeLV.
White blood cells: the cells that defend the body against disease-causing
organisms such as bacteria and viruses.
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