Virologists classify feline immunodeficiency virus (FIV) as a lentivirus (or "slow virus"). It is also in the same family as the human AIDS virus, with a few significant differences. FIV is in the same retrovirus family as feline leukemia virus (FeLV), but the viruses differ in many ways including their shape. FIV is elongated, while FeLV is more circular. The two viruses are also quite different genetically, and the proteins that compose them are dissimilar in size and composition. The specific ways in which they cause disease differ, as well.
Saliva to blood (biting) is generally accepted as the primary source of spreading the virus, and it is unlikely (but not impossible) that cats will spread FIV by drinking or eating out of the same food dish, or by mutual grooming. It is not surprising that outdoor cats are particularly susceptible to the virus, and the best way to prevent infection with FIV virus is to ensure that your cat stays indoors only, which eliminates the possibility of contact with FIV cats. Another, less common means of transmission is from the mother cat to her kittens during gestation, during birth, or by nursing. There is comfort in the fact that not all FIV queens pass the virus on to their kittens. This phenomenon is not fully understood, but all kittens from FIV mothers should be tested for the FIV antibodies after six months.
If your cat has been diagnosed as FIV-positive, you'll want to work very closely with your veterinarian in designing a management program. For cats with no other symptoms, and otherwise generally good health, this might simply be a matter of ensuring he gets a sound diet, possibly with added vitamins, anti-oxidants, and Omega 3/ Omega 6 fatty acids, as well as prompt, aggressive treatment of infections and other conditions as they crop up. Even flea control is important, as fleas transmit a number of other parasites such as the Haemabartonella. Also, flea bites themselves can become infected, which would be a cause for concern.
Infected cats may appear normal for years. However, infection eventually leads to a state of immune deficiency that hinders the cat's ability to protect itself against other infections. The same bacteria, viruses, protozoa, and fungi that may be found in the everyday environment--where they usually do not affect healthy animals--can cause severe illness in those with weakened immune systems. These secondary infections are responsible for many of the diseases associated with FIV.
Early in the course of infection, the virus is carried to nearby lymph nodes, where it reproduces in white blood cells known as T-lymphocytes. The virus then spreads to other lymph nodes throughout the body, resulting in a generalized but usually temporary enlargement of the lymph nodes, often accompanied by fever. This stage of infection may pass unnoticed unless the lymph nodes are greatly enlarged. An infected cat's health may deteriorate progressively or be characterized by recurrent illness interspersed with periods of relative health.
Sometimes not appearing for years after infection, signs of immunodeficiency can appear anywhere throughout the body. Poor coat condition and persistent fever with a loss of appetite are commonly seen. Inflammation of the gums (gingivitis) and mouth (stomatitis) and chronic or recurrent infections of the skin, urinary bladder, and upper respiratory tract are often present. Persistent diarrhea can also be a problem, as can a variety of eye conditions. Slow but progressive weight loss is common, followed by severe wasting late in the disease process. Various kinds of cancer and blood diseases are much more common in cats infected with FIV, too. In unspayed female cats, abortion of kittens or other reproductive failures have been noted. Some infected cats experience seizures, behavior changes, and other neurological disorders.
Antibody tests detect the presence of antibody in the blood of infected cats. Because few, if any, cats ever eliminate infection, the presence of antibody indicates that a cat is infected with FIV. This test can be performed by most veterinary diagnostic laboratories and also is available in kit form for use in veterinary clinics. Infected mother cats transfer FIV antibodies to nursing kittens, so kittens born to infected mothers may receive positive test results for several months after birth. However, few of these kittens actually are or will become infected. To clarify their infection status, kittens younger than six months of age receiving positive results should be retested at 60-day intervals until they are at least six months old.
A negative test result indicates that antibodies directed against FIV have not been detected, and, in most cases, this implies that the cat is not infected. Nevertheless, it takes eight to 12 weeks after infection (and sometimes even longer) before detectable levels of antibody appear, so if the test is performed during this interval, inaccurate results might be obtained. Therefore, antibody-negative cats with either an unknown or a known exposure to FIV-infected cats-such as through the bite of an unknown cat-should be retested a minimum of 60 days after their most recent exposure in order to allow adequate time for development of antibodies.
" Positive for FIV, ELISA test"
[Image from: http://www.veterinaria.org/revistas/vetenfinf/ar_geocities_com_vetenfinf4/felineimmunodeficiencyvirus/diagnosisarchivos/fivtest.jpg ]
On very rare occasions, cats in the later stages of FIV infection may test negative because their immune systems are so compromised that they no longer produce detectable levels of antibody.
Polymerase chain reaction (PCR) tests are designed to detect short segments of a virus's genetic material. While antibody-based tests are ideal screening tests for infection, in certain situations (such as confirming infection in antibody-positive kittens or determining infection of cats vaccinated with antibody-producing FIV vaccines), PCR-based tests, in theory, would be superior. Although PCR testing methods offer promise and are being actively explored, at this time unacceptable numbers of false-positive and false-negative results prevent them from routinely being recommended.
The only sure way to protect cats is to prevent their exposure to the virus. Cat bites are the major way infection is transmitted, so keeping cats indoors-and away from potentially infected cats that might bite them-markedly reduces their likelihood of contracting FIV infection. For the safety of the resident cats, only infection-free cats should be adopted into a household with uninfected cats.
Vaccines to help protect against FIV infection are now available. However, not all vaccinated cats will be protected by the vaccine, so preventing exposure will remain important, even for vaccinated pets. In addition, vaccination may have an impact on future FIV test results.
It is impossible to accurately predict the life expectancy of a cat infected with FIV. With appropriate care and under ideal conditions, many infected cats will remain in apparent good health for many months or years. If your cat has already had one or more severe illnesses as a result of FIV infection, or if persistent fever and weight loss are present, a much shorter survival time can be expected.
[Above info from: http://www.vet.cornell.edu/fhc/brochures/fiv.html]
On very rare occasions, cats in the later stages of FIV infection may test negative because their immune systems are so compromised that they no longer produce detectable levels of antibody.
Polymerase chain reaction (PCR) tests are designed to detect short segments of a virus's genetic material. While antibody-based tests are ideal screening tests for infection, in certain situations (such as confirming infection in antibody-positive kittens or determining infection of cats vaccinated with antibody-producing FIV vaccines), PCR-based tests, in theory, would be superior. Although PCR testing methods offer promise and are being actively explored, at this time unacceptable numbers of false-positive and false-negative results prevent them from routinely being recommended.
The only sure way to protect cats is to prevent their exposure to the virus. Cat bites are the major way infection is transmitted, so keeping cats indoors-and away from potentially infected cats that might bite them-markedly reduces their likelihood of contracting FIV infection. For the safety of the resident cats, only infection-free cats should be adopted into a household with uninfected cats.
Vaccines to help protect against FIV infection are now available. However, not all vaccinated cats will be protected by the vaccine, so preventing exposure will remain important, even for vaccinated pets. In addition, vaccination may have an impact on future FIV test results.
It is impossible to accurately predict the life expectancy of a cat infected with FIV. With appropriate care and under ideal conditions, many infected cats will remain in apparent good health for many months or years. If your cat has already had one or more severe illnesses as a result of FIV infection, or if persistent fever and weight loss are present, a much shorter survival time can be expected.
[Above info from: http://www.vet.cornell.edu/fhc/brochures/fiv.html]
