The virus does not survive long in the environment and is readily killed by common disinfectants. Rarely, the virus may also be spread by non-aggressive contact between cats eg, mutual grooming , from a pregnant queen to her kittens; and it can also be spread through blood transfusions. It is not known if blood sucking parasites such as fleas can spread infection so it is wise to maintain a regular flea control programme. FIV infects cells of the immune system white blood cells, mainly lymphocytes.
The virus may kill or damage the cells it infects, or compromise their normal function. In the first few weeks after infection the virus replicates and may cause mild signs of disease such as a mild fever and swollen lymph nodes. Usually these signs are so mild they go unnoticed. An immune response will develop which does not eliminate the virus, but keeps viral replication at a relatively low level. After a period of time, in some infected cats viral replication increases again, and it is typically these cats that go on to develop signs of disease.
In most cases this will probably be around years after the cat was first infected. Increased replication of the virus leads to progressive damage to the immune system.
The prevalence frequency of FIV infection varies in different cat populations. It tends to be more common where cats live in more crowded conditions and thus where cat fights are more common and tends to be much less common where cat populations are low and where cats are kept mainly indoors.
Infection is much more common in outdoor cats, and is about twice as common in male cats compared with female cats. Although cats of all ages can be infected, it is most commonly middle-aged cats years of age where infection is diagnosed.
FIV usually causes disease through immunosuppression — the normal immune responses of the cat are compromised, leading to an increased susceptibility to other infections and diseases. There are no specific signs associated with FIV, but typically infected cats will develop recurrent bouts of infections or diseases that gradually get worse over time, and infections may not respond to treatment as well as would normally be expected.
Other disease may also develop such as neoplasia eg, lymphoma and other infectious agents may be more problematic in FIV infected cats such as toxoplasmosis, haemoplasma infections, feline infectious peritonitis, etc. Most tests involve collecting a blood sample and detecting the presence of antibodies in the against the virus usually there is not enough virus in the blood itself to be able to readily detect it. It is important to remember that kittens born to FIV-infected queens will receive antibodies from the queen via the milk, and so will test positive early in life though they may not be infected.
Kittens with a positive test result should always be retested when they are months of age. Additionally, in countries where the FIV vaccine is available see below , cats that have been vaccinated will also test positive on the routine antibody tests, so alternatives such as a PCR test are needed.
Many FIV infected cats are able to live happily with the virus for a long period of time, and indeed the virus will not necessarily ever cause clinical disease. In one study, FIV-infected cats were found to survive just under 5 years on average from the time their disease was diagnosed compared with about 6 years for a similar group of non-infected cats. The main aims of managing an FIV-infection are to prevent further spread of infection to other cats and to maintain a good quality of life for the infected cat.
Some antiviral medications used in human patients with HIV infection have also been shown to help some cats with FIV infection. A vaccine against FIV has been licensed and is available in a number of countries. The available data suggests that the vaccine gives a useful degree of protection and that it might therefore be useful in cats at appreciable risk of being exposed to FIV. The vaccine cannot be expected to give complete protection though, especially as there are multiple different strains of FIV.
Also, a vaccinated cat will subsequently test positive on the routinely used antibody tests for FIV infection see above. FIV-infected cats should ideally be separated from other cats, but this can sometimes be difficult in a multicat household.
There have been several 'false dawns' in the pursuit of antiviral treatments effective against FIV. While there have been some published reports of effective treatment of the virus with human anti-retroviral drugs eg AZT used in the treatment of HIV and AIDS, any antiviral benefit is outweighed by negative effects on the patient such as anemia.
In any case, with careful management of any secondary problems such as gingivitis or chronic flu symptoms, most FIV-positive cats can enjoy a good quality of life for almost as long as an FIV-negative patient. As well as being susceptible to viral and bacterial infections, your cat is more likely to develop heavy burdens of parasites, even with a lower level of exposure. Hands, feet and clothing can easily carry fleas or worm eggs or larvae from outdoors, and regular deworming and flea treatments are essential.
Cats with FIV should never be fed raw meat as they are much more likely to suffer acute food poisoning, or infection with toxoplasma which can lead to serious illness or death. A balanced, good quality commercial cat food is the best diet for most cats, but especially those with immunodeficiency. While there has been some controversy about vaccinating an FIV-positive cat against the common diseases, notably the flu viruses and panleukopenia virus, FIV-positive cats that are generally well do respond well to vaccination.
They show appropriate increases in antibody levels after vaccination which are protective against these illnesses. However, there is a possibility that vaccination may promote viral replication through T-lymphocyte stimulation.
This seems to be a theoretical concern which has not been borne out through research to my knowledge, so in general most feline practitioners would recommend vaccination except in exceptional circumstances where the owner can guarantee that neither they nor their cats will be in contact with other cats. The most common route for the spread of most feline viral diseases is not direct contact between cats, but rather on fomites such as hands and clothing.
Speak to your veterinarian to assess your cat's individual risk of contracting disease. Unfortunately, you need to consider your FIV positive cat a risk to other cats. FIV is essentially a disease passed on through aggressive behavior, and as such there is a low risk of transmission between cats in a 'stable' household with the introduction of no new pets, and no major upheavals eg moving home, having an elderly relative moving in.
In the event of a major stress within the house, tempers may flare, and inter-cat aggression may become a problem. However, I do not usually advise my clients to separate their FIV-positive cats from the negative ones within the house. If a stress such as those mentioned above can be anticipated, then taking steps such as using Feliway to reduce aggression are advisable.
Of course, as well as the risk from your cat, your FIV-positive kitty is also more susceptible to contracting other illnesses from cats outdoors. While the risk to the other cats in your home may be very low, the same cannot be said for other cats your pet encounters outdoors. Territorial aggression is very likely to result in biting behavior, and even a relatively passive cat could potentially find themselves in a situation where they bite another animal, and thereby pass on this incurable illness.
This may be a huge challenge, but one cannot knowingly put somebody else's beloved pet at risk of contracting a long-term illness. If your cat has been used to having outdoor access, then it is vital that you try to replace some of the stimulation which outdoor living provides within the confines of your home. Climbing trees, laser pointers, and robotic mice are just a few of the things you can provide to make your home more stimulating and cat-friendly.
If you take nothing else from this article, I do want to convey that FIV is not a terminal illness. I have had more than one patient with FIV infection that lived beyond twenty years of age. With dedication from the owner, plenty of input from a committed veterinarian, an enriched environment, and good quality nutrition, your cat can live a long, healthy, and happy life.
Please use the comments section below if you would like to leave a message or have any questions regarding your cat. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
Im so glad I read these articles on FIV. My 11yr. Sexual contact is not a significant means of spreading FIV among cats. FIV-infected cats exist worldwide, but the prevalence of infection varies greatly. In North America, approximately 2. Rates are significantly higher 15 percent or more in cats that are sick or at high risk of infection.
Because FIV is transmitted through bite wounds, un-neutered male cats with outdoor access, especially those who are likely to fight with other cats, are at the greatest risk for FIV infection.
There is currently no vaccine commercially available in North America to protect against FIV, so the best way to reduce risk is to limit contact with cats who may be infected with the disease by keeping cats indoors and testing all cats within the household. There are three phases of infection with FIV - the acute phase, the asymptomatic or latent phase, and the progressive phase.
The acute phase of infection generally occurs months after infection. At this time, the virus is carried to 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 temporary lymph node enlargement that is often accompanied by fever, depression, and lack of appetite. This phase of infection may be very mild and is often missed by owners or attributed to other causes of fever.
Following the acute phase, cats will enter an asymptomatic phase, which may last for months to multiple years. During this time, the virus replicates very slowly within the cells of the immune system, and cats will not show any outward signs of illness.
Infected cats may exhibit blood work abnormalities, such as low white blood cell levels or increased blood proteins. Some cats will remain in this stage and never progress to more severe disease. As the virus continues to spread through the immune system, cats will enter a progressive immuno-compromised state during which secondary infections may occur. Most illness related to FIV is not from the virus itself, but from these secondary infections or problems with the immune system.
Cats may develop chronic or recurrent infections of the skin, eyes, urinary tract, or upper respiratory tract. Inflammation of the gums and severe dental disease, known as gingivostomatitis, is common in cats infected with FIV, and they are significantly more likely to develop cancer and immune-mediated blood disorders than healthy cats.
Weight loss, seizures, behavioral changes and neurological disorders are all possible. The severity of these illnesses can vary greatly, but once cats become ill with multiple critical infections or cancers, survival time is usually no more than a few months.
It is important that the FIV status of all cats be determined when they are first acquired, if they become ill, and regularly if they have any risk of exposure. When a cat is first infected with FIV, its immune system develops antibodies against the virus that persist in the blood for the rest of its life. To diagnose FIV, blood samples are examined for the presence of these antibodies. Because these tests check for antibodies to the FIV virus rather than the virus itself, there are a few scenarios when a single test is not sufficient to determine if a cat is truly infected with FIV or not.
A negative antibody test indicates that the cat has not produced antibodies against the FIV virus and, in the vast majority of cases, indicates that the cat is not infected. There are two scenarios in which negative results may occur in infected cats.
It takes the body between 2 and 6 months to develop enough antibodies against FIV to be detected, so if a cat had been infected very recently, it may test negative for FIV even though it is truly infected. If exposure is possible, it is recommended that cats are retested after at least 60 days to get a more accurate result.
On very rare occasions, cats in the later stages of FIV infection may test negative on FIV antibody tests because their immune systems are so compromised that they no longer produce detectable levels of antibody.
Because few, if any, cats ever eliminate infection, the presence of antibodies indicates that a cat is infected with FIV.
Because false positives are possible, it is recommended that positive results in healthy cats are confirmed using a second technique mentioned above. There are two scenarios where a positive antibody test may not represent true infection. 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.
0コメント