Colony Management – FIV and FeLV


FIV and FeLV are incurable viruses that only affect cats. Humans cannot catch or transmit these viruses.

Not all cats that become infected will develop disease. Cats that test positive for FIV often live long, healthy lives. Many veterinary spay and neuter clinics do not test feral cats for FeLV or FIV, because most feral cats enjoy excellent health and are no more likely to be infected with disease than owned cats. In fact, owned cats and feral cats contract FeLV and FIV at an equally low rate (about 4%).

Feral Cat FOCUS does not support the euthanasia of healthy cats that test positive for FeLV and FIV.

Feral Cat FOCUS does not support testing feral cats for FIV and FeLV:

  • The percentage of feral cats infected with either FeLV or FIV is low. Studies detected FeLV in 4.3% of cats; FIV in 3.5%. This is similar to the rate in owned cats. Several large-scale spay/neuter clinics in the U.S. report only a 1-2% incidence of FeLV in the early years when every cat is tested.
  • Test results can be unreliable and can result in false positives. Cats testing positive should be re-tested at least 28 days after the cat’s last possible exposure to the virus.
  • Spaying or neutering cats inhibits the spread of the viruses. Since spaying and neutering reduces or eliminates the primary modes of transmission, such as fighting and breeding, infected cats pose less risk to other cats.
  • Infected cats are often asymptomatic and can remain healthy with no sign of illness for many years or for their entire life; considering all factors, more cats likely die from having positive test results than die from FIV-related disease.
  • And testing can be prohibitively expensive. The cost of testing (and often re-testing because of false positive test results) hinders the success of a spay/neuter program. The goal of the program is to spay or neuter as many cats as possible. Resources are best applied to spaying and neutering more cats. And, increasing the number of cats that are spayed or neutered decreases the incidence of virus transmission
  • FIV tests do not differentiate between FIV infection and FIV vaccination. A positive test is likely to result in euthanizing vaccinated cats that are not infected.