The Truth about FIV and FeLV
Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) are two
of the most important infectious diseases of cats worldwide. So much is
misunderstood about these diseases. Big Sid's mission is to help educate
people about FIV and FeLV. Unbelievably in this day and age, some veterinarians
still recommend euthanizing cats that test positive.
Please read on to educate yourself and put to rest unnecessary fears about
FIV and FeLV.
The Feline Immunodeficiency Virus is a slow virus that affects a cat's immune
system over a period of years. FIV is a cat-only disease that cannot be spread
to humans or other animals. FIV cats most often live long, healthy and
relatively normal lives with no symptoms at all.
The disease has a wide range of effects. The cat can fight off the infection
and become totally immune, can become a healthy carrier that never gets sick
itself, or a mid-level case in which the cat has a compromised immune system.
FIV is not easily passed between cats. It cannot be spread casually like
in litter boxes, food and water bowls or when snuggling and playing. The virus
can be spread through blood transfusions, badly infected gums, in-utero from
mother to offspring or penetrating bite wounds (typically associated with
unneutered tom cats). A neutered cat in a home is extremely unlikely to
infect other cats, if properly introduced.
FIV-positive cats should be kept as healthy as possible feeding them a
high quality diet. As with all cats, they should be kept indoors and
free from stress. Treat any secondary problem, such as an upper respiratory
infection, as soon as they arise.
Feline Leukemia Virus is a disease in cats that can cause anemia and lymphoma,
among other illnesses. The virus can also suppress the cat's immune system
affecting their ability to fight off bacteria.
FeLV positive cats may live many years in a healthy state. A little more
than half of the cats that test positive for the virus develop antibodies
and are able to fight it off. A little less than half of the adult cats
that test positive for FeLV will succumb to the disease.
FeLV is commonly transmitted through saliva. Therefore mutual grooming,
nose-to-nose contact, and shared food and water bowls can be sources of
infection. It takes large amounts of virus to infect an adult cat, so
usually prolonged contact or a bite is necessary for transmission.
Vaccinating against FeLV helps to control the spread of the virus.
FeLV cats should be kept indoors, both to protect them from exposure
to disease, and also to prevent them from spreading FeLV to other cats.
Caring for cats with FIV or FeLV
The goal of caring for FeLV and FIV infected cats is to keep them healthy,
detect problems early and treat the associated diseases promptly and
aggressively so that the cats can enjoy the maximum quantity and quality
of life possible.
For a personal perspective on having FeLV and FIV cats, see
Abel's Featured Cat
FIV is difficult to transmit, the main route is via a bite where the virus is actually injected into the bloodstream
There is often confusion between FIV and FeLV, this is particularly the case regarding the transmission of the virus.
The FIV virus is present in the saliva, and for transmission to another cat to take place, the live virus has to enter the bloodstream of the recipient cat.
There are two main reasons why FIV isn't transmitted via shared bowls or mutual grooming as is sometimes wrongly suggested:
Firstly the virus is very fragile, and does not live for long once outside the body - it is destroyed by drying, light, heat and basic detergents - normally the virus will be long-dead before any surfaces come to be cleaned, it is the initial drying that sees off the vast majority of the virus, and this will normally happen in seconds.
This is why the route of transmission is primarily via a bite, where the still wet saliva containing the live virus is effectively injected through the skin directly into contact with the blood of the recipient cat.
The second reason is that the mucous membrane is a fairly effective barrier to the virus, so even if some virus does enter the cat's mouth, it is very unlikely to cross the mucous membrane, so will likely die within the stomach. It has been suggested that, for the virus to actually infect a cat when taken in through the mouth, there would need to be ten thousand times as much virus present for it to achieve a cross infection.
Interestingly, this is confirmed by the fact that kittens born to an FIV+ mother are rarely infected with the virus - although the kittens are not infected directly in the womb, as the placenta will protect them, the virus is present in the mother's milk, so all kittens will have prolonged exposure to the live virus in their digestive systems, yet it is very uncommon for the kitten to actually become infected - this is testiment to how effective the mucous membrane must be in preventing transmission.
It is for these reasons that the often-prescribed "keep separate from other cats" is NOT valid. FIV cats can live communally with non-FIV cats with very little risk of the virus being transmitted between them - unless the cat is a fighter and gives another cat a serious bite, which is rare with properly introduced household cats. The vast majority of cats, once neutered, will not bite other cats they live with - they may play and scrap, but this rarely leads to the serious bite required to inject the virus. There are numerous examples of households with large numbers of cats living together with FIV-positive cats without the virus being transmitted. A slow and careful introduction is required when bringing any new cat into an existing household, especially so with an FIV cat.