The Feline Immunodeficiency Virus (FIV) is categorized as a lentivirus – a genus of slow viruses belonging to the family of retroviruses, characterized by a delay in the onset of symptoms/a long incubation period after infection occurs. FIV belongs in the same family of viruses as the Human Immunodeficiency Virus (HIV). As retroviruses are specific to the species, FIV will only infect felines, just like how HIV will only infect humans. FIV in cats is fairly common.
Despite being in the same retrovirus family, FIV should not be mistaken with the Feline Leukemia Virus (FeLV). These two diseases are often mistaken for the other as they cause similar secondary conditions, but they are quite different genetically and protein composition.
FIV is a disease that can be found worldwide, able to infect both domesticated and wild felines. It is most prevalent in wild, outdoor cats, as well as in heavily [feline] populated areas. Male cats are more prone to contracting FIV as compared to female cats, and high-risk cats (e.g. Those with weak immune systems) are more susceptible to FIV as compared to healthy cats (15-20% as compared to 1-5% respectively). Infection is most commonly seen in middle-aged cats (5-10 years). As such, because bite wounds and scratches are the most common causes of transmission, the disease most frequently infects free-roaming, outdoor male cats. Other forms of transmission include sexual transmission and transmission during birth (in utero/through mother’s milk).
Stages of Infection
FIV has three stages of infection: acute (initial), latent (asymptomatic), and the final stage.
During the acute stage, the virus causes mild symptoms such as lethargy, fevers, swollen lymph nodes, and weight loss. Additionally, the infected feline may experience increased susceptibility to skin and/or intestinal infections. This stage occurs 4-6 weeks after exposure to the virus.
During the latent stage, visible signs of infection, do not occur. The duration of this stage ranges from a few months to a few years. Immunodeficiency occurs during this stage, and when it reaches a severe level, the final stage occurs.
During the final stage, the infected feline will be extremely susceptible to contracting secondary diseases/infections. Oftentimes, these diseases would not normally cause severe problems in healthy cats, but the immune system is unable to fight off said diseases due to the heavily impaired state of the system of a cat with FIV. Common diseases and infections include respiratory tract and intestinal infections. When a disease progresses into a later stage, the life expectancy of the infected feline is shortened drastically.
Clinical Signs of Disease
In addition to the signs observed during the acute stage of FIV, these are the clinical signs of disease:
Usually diagnosed through blood tests, FIV is detected through the presence of antibodies to the FIV virus found in the blood. If the test result shows that there are antibodies present in the blood, the feline is determined to be FIV positive. Note that multiple tests are recommended in order to confirm a positive or negative result, as no test is fully accurate.
If the blood test comes up negative, it does not necessarily mean that the feline in question is FIV free. As it takes a considerable amount of time (8-12 weeks on average) for a detectable level of antibodies to appear in the blood, cats should be retested in 3 months if potentially exposed to FIV.
Cat owners should note that it is possible for infected mothers to pass on FIV antibodies to her kittens, which may then lead to a positive result on the FIV test even if they did not contract FIV. These antibodies, however, can be cleared from the kittens’ systems over the course of a few months, until they hit six months of age. When these antibodies have been purged from their systems, the kittens will then be tested negative for FIV. Therefore, kittens should be retested after they turn six months old to see if they have contracted FIV.
Management & Care
Currently, there is no treatment that targets the FIV virus, but there are treatments that can help an infected feline cope with secondary infections caused by the virus. For example, the veterinarian may prescribe medication for secondary diseases, anti-inflammatory and immune-enhancing drugs, as well as electrolyte and fluid therapy if the feline is experiencing dehydration.
FIV infected felines should be kept indoors in order to minimize exposure to infectious agents carried by other animals and to prevent the spread of FIV to other felines in the neighborhood. Infected felines should also be neutered or spayed.
Infected cats should be placed on a healthy and nutritionally complete diet – uncooked food and any unpasteurized dairy food items should not be fed to infected cats due to the higher chances of them contracting diseases through bacteria and/or parasites present in these foods.
Checkups should occur at least twice a year, and owners of FIV infected cats should be on a constant lookout for any declines in health.
Although untreatable, felines suffering from FIV can live for many years if provided with the best care. Keeping felines indoors and away from stray cats can best prevent FIV infections. If there is a possibility that your cat has been exposed to FIV, FIV testing should be performed as soon as possible. An early detection can help the feline – and the rest of the family – cope more easily with the disease.