Everyone is familiar with the human immunodeficiency virus (HIV) – the retrovirus that causes acquired immunodeficiency syndrome (AIDS) in people. Although HIV can only infect humans and some primates, cats can be infected by a very similar virus from the same genus (Lentivirus) with a similar name – feline immunodeficiency virus (FIV). The FIV virus is transmitted from cat to cat by contact with blood, usually through a cat bite.  In Canada and the USA, up to 3% of healthy cats may be infected with FIV.

As with HIV in people, FIV attacks a cat’s immune system, which can leave the animal susceptible to many different infections that a healthy cat could normally fight off. Some of these infections, like toxoplasmosis, are similar to those that occur in AIDS patients. (More information on toxoplasmosis and Toxoplasma is available on the Worms & Germs Resources page). Depending on a number of factors, an FIV-positive cat may remain healthy for years, but once the animal begins to show signs of a weakened immune system, it will often develop chronic or recurrent health problems. The infection is life-long – there is no “cure” for FIV.

Some key points to remember:

  • Cats cannot get HIV. People cannot get FIV. They are related but different viruses.
  • Keeping your cat indoors will prevent fighting with other cats and decrease the risk of your cat contracting FIV.
  • There is a vaccine available for FIV, but it remains uncertain if the vaccine can protect cats from all strains of the virus.  The vaccine also interferes with tests for FIV infection.  Therefore, preventing exposure to the virus is still the best way to prevent FIV infection.
  • If your cat already has FIV, it is important to keep it indoors to decrease exposure to pathogens that could make your cat sick, and to prevent your cat from spreading the virus to other cats.

More information about FIV can be found on the Cornell Feline Health Center website.Orange Kitten