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Feline immunodeficiency virus
Feline immunodeficiency virus (FIV) is a chronic viral disease that progressively weakens a cat's immune system. It makes the animal more vulnerable to infections and certain illnesses. The progression is often slow, with symptom-free phase...
What is it?
Feline immunodeficiency virus (FIV) is a chronic viral disease that progressively weakens a cat's immune system. It makes the animal more vulnerable to infections and certain illnesses. The progression is often slow, with symptom-free phases that can last for years.
The disease is caused by the feline immunodeficiency virus (FIV), a lentivirus similar to human HIV but specific to cats. This virus attacks immune system cells, reducing the body's natural defenses.
Unneutered male cats that live outdoors and fight frequently are the most exposed. Living with an infected cat or having free outdoor access also increases the risk.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Signs include fever, fatigue, loss of appetite and weight loss. Recurrent infections of the mouth (gingivitis, stomatitis), eyes or skin are often observed. Swollen lymph nodes and poor wound healing may also occur.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Transmission
FIV is mainly transmitted through deep bite wounds during cat fights, as the virus is present in saliva. Transmission from mother to kittens is possible but rare, as is sexual transmission.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
If FIV is suspected, only a veterinarian can confirm the diagnosis with appropriate tests and recommend proper follow-up. A cat carrying FIV can live a long life with regular veterinary monitoring and a calm environment. Always consult a veterinarian for any concerns about your cat's health.
Prevention
Neutering reduces fighting and thus the risk of transmission. Keeping cats indoors and avoiding contact with stray or infected cats also limits exposure. Testing before adopting a new cat is recommended.
References
Content reviewed by the TunisieVet editorial team · Updated 08 August 2026
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This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
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