Feline Immunodeficiency Virus (FIV)

Also called: Feline AIDS (late-stage term)

• Cats
• Infectious (viral)
• Adult

FIV is a lifelong viral infection that gradually weakens a cat's immune system, leaving it vulnerable to other infections — somewhat like HIV in people, but FIV only infects cats and cannot infect humans. It is mainly spread through bite wounds during fighting, so outdoor, roaming, entire male cats are most at risk. Many infected cats stay healthy for years, and a diagnosis is not on its own a reason for euthanasia.

Signs to look for

• Often none for a long period
• Recurrent or persistent infections (mouth, skin, respiratory, eyes)
• Chronic gingivitis/stomatitis (inflamed gums and mouth)
• Weight loss
• Poor coat
• Enlarged lymph nodes, fever, lethargy

How a vet diagnoses it

Blood tests detecting FIV antibodies (point-of-care test), with confirmatory testing (e.g. PCR) in some situations, as vaccination history and maternal antibodies can complicate interpretation.

Treatment

No cure. Management focuses on excellent basic care, keeping the cat indoors (to protect it and prevent spread), prompt treatment of secondary illnesses, neutering, good nutrition, and regular vet checks.

Monitoring at home

General health, body weight, dental/oral health, and early detection and treatment of secondary infections — more thorough routine monitoring than for a healthy cat.

Who tends to get it

Adult, outdoor-access, entire male cats that fight are at highest risk. Australian context: FIV is notably common in outdoor cats — Australian studies have found around 15–16% of outdoor-access client-owned cats positive. Keeping cats indoors or in secure enclosures is recommended.

Sources

• Cornell Feline Health Center — FIV
• International Cat Care — FIV