FIV Facts

FIV and Adult Cats

This study in the Veterinary Journal shows FIV is difficult to transmit. How many cats’ lives have been lost because people believed the opposite?

  • It is most commonly transmitted through blood contamination from deep, penetrating bite wounds.
  • Even though FIV and HIV are similar, humans are NOT at risk for contracting the FIV virus from an infected cat.
  • FIV can only be spread between cats. Unaltered, outdoor cats of breeding age are at the greatest risk for infection.
  • Kittens can test positive for the FIV virus, due to antibodies from an FIV+ mother, but only a small percentage are really infected.Kittens should be tested at 6 months of age, or later, for the most accurate results.
  • There is a vaccine available to protect cats from becoming infected with the FIV virus, but we do not recommend using this.
    • FIV virus replicates so rapidly that the vaccine is only minimally effective against a very few strains of the virus.
    • A vaccinated cat will test positive for the virus. Therefore, if a vaccinated cat should stray from home and end up in a shelter, it will likely be killed, due to being FIV positive.
  • The best way to prevent the spread of FIV is to spay and neuter your pets and keep them indoors.

FIV and Kittens

FIV is not easily passed between cats. It cannot be spread casually in litter boxes, water and food bowls, or when snuggling and playing. It is rarely spread from a mother to her kittens. The virus can be spread through blood transfusions, badly infected gums, or serious, penetrating bite wounds.  Kittens born to an FIV mother will inherit her antibodies, but rarely the virus.

A mother cat with FIV will have FIV antibodies which are produced by her immune system in response to the virus. When pregnant, she will pass these antibodies to her kittens through the blood, but she does not pass the virus, as it will not cross the placenta.  Because the usual test for FIV searches for the antibodies and not the virus, a kitten from an FIV+ mother will show positive on the test without any virus being present. As the kittens grow, they will gradually lose their inherited protection, and will then test negative. This can take several months and the actual time varies between kittens, so any FIV+ positive test is not safe until the kitten is at least six months old, and possibly older.

Kittens who truly test positive for FIV, are not common. The virus is present in the milk, yet it is rare that the kittens will inherit the virus from their mother.  This shows how hard it is to transmit the virus across the mucous membrane, indicating that the virus is not at all contagious.  If a kitten is indeed found to be FIV+, it is mistakenly believed that their life may be shorter than most because they were infected before their immune system was developed. However, we have heard of FIV+ kittens that have remained healthy and not picked up general sniffles and runny eyes when their non-FIV+ siblings have done so, so we are not sure just how they are affected.  FIV-positive cats should be kept as healthy as possible. Keep them indoors and free from stress, feed them a high-quality diet and treat any secondary problems as soon as they arise.