What is FIV?

Feline Immunodeficiency Virus (FIV) is a lentivirus closely related to HIV in humans. Often called "cat AIDS," FIV attacks and gradually destroys the immune system, leaving infected cats vulnerable to a wide range of secondary infections and illnesses. Unlike the alarming nickname suggests, FIV is a manageable condition — many FIV-positive cats live long, comfortable lives with proper care.

FIV is found worldwide and is estimated to affect 2–5% of the cat population, with higher rates among free-roaming, unneutered male cats.

How FIV Progresses

FIV infection progresses through stages:

Acute Phase (weeks to months after infection)

  • Mild fever
  • Swollen lymph nodes
  • Temporary decrease in white blood cells
  • Many cats show no obvious symptoms

Latent Phase (months to years)

  • The virus is present but the cat appears healthy
  • This phase can last many years
  • The immune system gradually weakens

Symptomatic Phase

  • Chronic or recurrent infections (respiratory, oral, skin, urinary)
  • Chronic gingivitis and stomatitis (severe mouth inflammation)
  • Weight loss
  • Poor coat condition
  • Chronic diarrhea
  • Enlarged lymph nodes
  • Neurological issues (in some cats)
  • Increased susceptibility to certain cancers

Transmission

FIV is primarily transmitted through deep bite wounds, making it most common among:

  • Unneutered male cats that fight over territory
  • Free-roaming outdoor cats
  • Cats in multi-cat households with aggressive interactions

FIV is not easily transmitted through:

  • Casual contact (grooming, sharing food bowls)
  • Airborne transmission
  • Litter box sharing

Mothers can transmit FIV to kittens in utero or through nursing, though this is less common.

Testing

When to Test

  • All cats should be tested when first adopted
  • Before introducing a new cat to the household
  • After any potential exposure (bite wounds from unknown cats)
  • Cats showing signs of illness
  • Kittens born to FIV-positive mothers (test at 6 months+, as maternal antibodies can cause false positives)

Test Methods

  • ELISA/SNAP test: Rapid in-clinic test detecting antibodies; very reliable in adult cats
  • Western blot or IFA: Confirmatory tests if the initial result is ambiguous
  • PCR: Detects viral DNA; useful for kittens under 6 months

Living with an FIV-Positive Cat

FIV-positive cats can live 5–10+ years after diagnosis with good care:

  • Keep indoors to prevent spreading FIV and to reduce exposure to other infections
  • Spay or neuter to reduce fighting behavior and prevent transmission
  • Feed a high-quality diet to support immune function
  • Veterinary checkups every 6 months to catch problems early
  • Promptly treat any infections or dental issues
  • Minimize stress to reduce immune suppression
  • Vaccinate appropriately (discuss with your vet, as some vaccines are less effective)

Can FIV Cats Live with Other Cats?

Yes, if managed properly. FIV is not easily spread through casual contact. In stable, friendly multi-cat households where cats don't fight, the risk of transmission is very low. However, introductions should be done carefully, and all cats should be tested.

Important Facts

  • FIV cannot be transmitted to humans or dogs
  • There is no cure, but the disease can be managed
  • Neutering male cats dramatically reduces FIV transmission in communities
  • FIV-positive cats should never be euthanized solely based on their FIV status
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