Biology 103
2000 First Web Report
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The feline leukemia virus, or FeLV as it is commonly known, is a very deadly and easily transmitted disease. FeLV is so dangerous because the virus is spread through the saliva and tears of cats (1). This may not seem to be a large problem for people who do allow their cats contact with other cats, but there are complications that make the virus easily transmittable. For example, the virus is transmitted between cats that share a food or water dish and cats grooming each other. It is also possible that a mother carrying the disease can transmit the virus to her kittens before birth (2) . A cat can also be a carrier for the virus. In these cases, a cat would not exhibit any obvious signs of the virus, but could still transmit the virus to another cat with whom he/she has contact as described above. It is for these reasons why FeLV can be spread very easily among cats that stay in doors most of the time and do not come into contact with street cats who most commonly carry the virus.

Once a cat has become infected with the virus there are a series of treatments that may help the cat recover. It is crucial that the cat receives treatment ASAP. The word leukemia means cancer of the white blood cells. When the virus enters the blood stream the virus may be treatable until the virus infects organs such as the lymph nodes, intestinal tract, kidneys, liver, spinal cord, brain, bone marrow and blood (2) . Once the virus reaches this stage, the possibility for complete recovery are very slim. Another possibility is that the virus will suppress the immune system in which case the cat will be more likely to catch other diseases and infection that could be serious.

In the primary stage of infection, there currently exist two FeLV tests. The first of these is called ELISA which detects the presence of the virus in the blood stream and in the bone marrow. The second test is called IFA. This test shows whether or not the virus has reached the second stage when the bone marrow is permanently infected. On many occasions the tests results are not the same. This results from the fact that the tests detect the virus at overlapping stages. Thus, if the ELISA test is negative, it is possible that the virus has moved to the bone marrow and will be detected with the IFA test (1).

The worst aspect of Feline Leukemia is that there is currently no cure. It is true that there exists a chemotherapeutic treatment that can produce a temporary remission in some cats. This therapy allows the cat to live normally for a period of several weeks to several months. It should be stressed that the chemotherapy can be very stressful on the infected cat and that these treatments are only temporary. The only cause the symptoms to go into remission. The therapy is not a permanent cure. Other treatments include massive dosages of vitamin C in an effort to help the immune system fight off infection. Another possibility is steroid treatment. A steroid called prednisolone decreases the numbers of some circulating white blood cells. A cat with FeLV might have many cancerous blood cells circulating in the blood stream and the steroid would decrease the number of cancerous cells (1). Both of these treatments do not insure that a cat will be completely cured. In fact, the cat will probably not be completely free of the virus after such treatments.

However, there are some statistics that are leading scientists to believe there may be a natural immunity to the virus in some cats. First of all, 30% of exposed cats do not become infected and approximately 60% of exposed cats do not die from the virus. For example, if 100 adult cats were exposed to the virus, 30 would not be infected. Of the 70 cats infected 35 would be immune. The remaining infected 35 cats, who are not immune, would eventually die of the disease (3). Thus, not all cats who come into contact with the virus will die from FeLV. The chances are still not great that your cat would be one of the 30% not infected. The best idea is to protect your cat from any possible infection of FeLV.

WWW Sources

2)The Animal Clinic Web Site

3)The Animal Health Index Web Site, This site contains a lot of practical information about feline leukemia that is easy to read and understand

4)The Feline Advisory Bureau Web Site

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