Feline immunodeficiency virus

File:Phylogenetic-tree-of-72-nonidentical-FIV-from-7-carnivore-species-based-on-a-region-of.png

A virus that affects cats, similar to HIV in humans

Feline immunodeficiency virus (FIV) is a lentivirus that affects cats worldwide. It is in the same family as the human immunodeficiency virus (HIV) and causes a disease in cats that is similar to acquired immunodeficiency syndrome (AIDS) in humans. FIV compromises the immune system of infected cats, making them more susceptible to various infections and diseases.

Virology

FIV is a member of the Retroviridae family and the Lentivirus genus. Like other lentiviruses, FIV is an RNA virus that uses the enzyme reverse transcriptase to convert its RNA into DNA within the host cell. This DNA is then integrated into the host's genome, where it can remain latent for extended periods.

The virus primarily targets CD4+ T cells, which are crucial for the immune response. Over time, the depletion of these cells leads to immunodeficiency, making the cat vulnerable to opportunistic infections.

Transmission

FIV is primarily transmitted through bite wounds, as the virus is present in the saliva of infected cats. It is most commonly spread during aggressive encounters, which is why intact male cats, who are more likely to fight, are at higher risk. Unlike HIV, FIV is not typically spread through sexual contact or casual contact such as grooming.

Clinical Signs

The clinical progression of FIV infection in cats can be divided into three stages:

1. Acute Phase: This occurs 4-6 weeks after infection and may present with mild symptoms such as fever, lymphadenopathy, and leukopenia.

2. Asymptomatic Phase: This phase can last for years, during which the cat appears healthy but the virus is actively replicating in the lymphoid tissues.

3. AIDS-like Phase: In this final stage, the cat's immune system is severely compromised, leading to secondary infections, weight loss, and other chronic health issues.

Diagnosis

Diagnosis of FIV is typically made through serological testing, which detects antibodies to the virus in the cat's blood. The most common tests are the ELISA and Western blot tests. It is important to note that kittens born to FIV-positive mothers may test positive due to maternal antibodies, so retesting is recommended after six months of age.

Treatment and Management

There is currently no cure for FIV, but infected cats can live long, healthy lives with proper management. Treatment focuses on maintaining a good quality of life and preventing secondary infections. This includes regular veterinary check-ups, a balanced diet, and minimizing stress.

Antiviral drugs, such as zidovudine (AZT), have been used in some cases to reduce viral load and improve clinical signs, but their use is not widespread due to potential side effects.

Prevention

Preventing FIV involves reducing the risk of exposure to the virus. This includes keeping cats indoors to prevent fights with infected cats and neutering male cats to reduce aggressive behavior. A vaccine for FIV is available in some countries, but its efficacy is variable, and it may interfere with serological testing.

Also see

• Feline leukemia virus
• Retrovirus
• Lentivirus
• Human immunodeficiency virus