Feline Immunodeficiency virus (FIV)

Feline immunodeficiency virus (FIV) is a viral infection that attacks the immune system of cats. It is also known as Feline acquired immunodeficiency syndrome (Feline AIDS) and commonly referred to by the letters "F-I-V". The immunodeficiency caused by the virus can promote a variety of symptoms including: infections caused by the poorly functioning immune system, anemia and low blood-cell counts, infections of the gums and mouth, cancer or neurologic disease.

FIV is a retrovirus similar to the Human Immunodeficiency Virus (HIV also known as AIDS). FIV is not contagious to people; it is an infectious disease spread from cat to cat, primarily by biting and scratch wounds. FIV has been found in the mother's milk and can be transmitted from mother to kitten. Experimentally, FIV can also be transmitted through semen however this is not thought to be a significant method of transmission in nature. Transmission among household cats through normal contact is thought to be unlikely. Outdoor and male cats are predisposed.

FIV has three stages of infection. They include an acute phase associated with various symptoms, which includes infections, fever and lymph node (gland) enlargement. The second phase is called the subclinical phase, which lasts from months to years, during which time many cats appear healthy. The third phase is chronic infection, also known as the terminal phase, which is associated with deterioration of the immune function and that predisposes cats to a variety of infections.

Infection is thought to involve between one and 14 percent of the cat population. Co-infection with feline leukemia virus (FeLV) can occur.

What are the signs?

Many cats are diagnosed on a routine blood screening and are asymptomatic. If the FIV is causing active infections, sign will vary depending on the secondary problem caused.

Weight loss
Gingivitis (inflammation of the gums)
Reduced appetite
Fever
Enlarged lymph nodes
Nasal or ocular (eye) discharge
Chronic infections not responsive to treatment
Chronic diarrhoea

Veterinary care should include diagnostic tests and subsequent treatments. Diagnostic tests are needed to recognize FIV and exclude other diseases.

Tests may include:

Complete medical history and physical examination

Blood test called the Enzyme-lined immunosorbent assay (ELISA) test should be done. The ELISA detects anti-FIV antibodies in the serum or saliva.

Results can be difficult to interpret in cats less than six months of age because some cats may still carry antibodies from their mother that is positive for FIV without actually being infected. These antibodies are generally gone from kitten by 6-months of age.

These tests will also be positive if the cat has been vaccinated for FIV. For this reason, only unvaccinated cats should be tested and every cat should be tested before the first FIV vaccination.

All positive test results should be confirmed with a second test called the Western blot or Polymerase chain reaction (PCR) test. Feline leukemia testing should also be completed to determine if this infection also exists.

What is the treatment?

There has been no proven cure for FIV infection, several treatment options, supportive care, and symptomatic therapies are important, including:

Antibiotics for bacterial infections

Nutritional support 

Parasite control

Keeping the cat indoors and isolated from other cats

Biopsy and removal of tumors

After Care

Administer prescribed medications and monitor your cat's general activity level, body weight, appetite and attitude. Provide quality nutrition and schedule veterinary visits to monitor the condition.

Keep all FIV infected cats indoors to decrease exposure to other cats. It is ideal to isolate FIV infected cats from negative cats, however, as mentioned earlier transmission among household cats through normal contact is thought to be unlikely although it is possible.

For cats with FIV, preventative health care and dental care with antibiotic coverage prior to the procedure is often recommended in infected cats. Vaccination for other diseases should be discussed with your veterinarian. If yearly vaccinations are given, only killed vaccines, which are vaccines made up of killed virus, as opposed to other types where live virus may have been modified, should be utilized to protect a potentially inadequate immune system in infected cats.

Preventative Care

Feline immunodeficiency virus is an infectious disease that can be prevented primarily by eliminating interactions with infected cats. Keeping your cat indoors is the most effective way to prevent FIV. Test all new cats prior to bringing them into your home and exposing them to your other cats. Recently, a vaccine has been developed that can help reduce the risk of acquiring FIV in at-risk cats. This is most beneficial in indoor/outdoor cats, outdoor cats or cats exposed to many new cats.

Other prevention methods include to neuter males (to minimize or prevent fighting). It is also recommended to isolate, test and treat infected cats.

Information In-depth

Other medical problems can lead to symptoms similar to those encountered in feline immunodeficiency virus. It is important to exclude these conditions before establishing a diagnosis of FIV infection. These conditions include: 

Anemia

Ehrlichiosis, an infectious disease caused by unusual bacteria called rickettsia that live inside of white blood cells or platelets

Rocky mountain spotted fever, an infectious disease caused by another rickettsial agent

Feline leukemia virus (FeLV) infection

Feline infectious peritonitis (FIP), a viral disease of cats

Fungal infections such as cryptococcosis, histoplasmosis, blastomycosis and coccidioidomycosis

Toxoplasmosis, an infectious disease caused by a protozoa that completes its life cycle in cats

Hemobartonella felis, an infectious disease caused by a bacterial parasite that lives in red blood cells

Leukemia, cancer of blood-forming tissues with spread of cancer cells through the bloodstream

Lymphoma, solid tumor of the lymphoid tissues that produce lymphocytes

Multiple myeloma, a tumor of the antibody-producing B-type lymphocytes

Myeloproliferative disease, cancer of the white blood cell producing bone marrow tissue

Other forms of cancer

Sepsis, body wide infection caused by spread of bacteria or their toxins in the bloodstream

Systemic lupus erythematosus, a disease in which the body's immune system mistakenly recognizes certain body tissue components as foreign and attacks them.

Disclaimer

This pet health article is for reference only.

If your pet is showing any symptoms or distress, and you suspect your pet is ill CONTACT YOUR VET IMMEDIATELY.