Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) are incurable viruses that only affect cats. Humans cannot catch or transmit these viruses. Not all cats who become infected will develop the disease.
Cats who test positive for FIV often live long, healthy lives. Many spay and neuter clinics do not test for FeLV or FIV, because most community cats are no more likely to be infected with the virus than owned cats and will live healthy lives outdoors. In fact, owned cats and community cats contract FeLV and FIV at an equally low rate of about 4 percent.
A growing number of animal shelter and veterinary professionals are changing their protocols to no longer test all cats for FIV and FeLV. They are recognizing that the indiscriminate testing is unreliable, wasteful, and dangerous for cats.
Alley Cat Allies has long advocated against routinely testing cats for FIV and FeLV for multiple reasons:
- The percentage of community cats infected with either FeLV or FIV is low. One study detected FeLV in 4.3 percent of community cats and FIV in 3.5 percent, which are similar to the rates in owned cats. Several large-scale Trap-Neuter-Return (TNR) programs report a 1 to 2 percent incidence of FeLV.
- Test results can be unreliable and result in false positives. Cats testing positive should be retested at least 28 days after their last possible exposure to the virus.
- Spaying or neutering cats inhibits the spread of the viruses. Spaying and neutering reduces or eliminates the primary modes of transmission, such as fighting and causing bite wounds, and breeding.
- Infected cats are often asymptomatic and can remain healthy with no signs of illness for many years or for their entire lives.
- Testing can be prohibitively expensive. The cost of testing (and often retesting due to false positive test results) hinders the success of a spay and neuter program. Resources are best applied to spaying and neutering more cats. Increasing the number of cats who 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 who are not infected.
Alley Cat Allies does not support the killing of healthy cats who test positive for FeLV and FIV. The American Association of Feline Practitioners also recommends against routine “euthanasia” of healthy FeLV- and FIV-positive cats. Euthanasia should only be used to relieve suffering from a terminal or incurable condition. Cats showing signs of illness or injury should be trapped and taken to a veterinarian for medical treatment. Learn more about the difference between euthanasia and killing.
 Prevalence of feline leukemia virus infection and serium antibodies against feline immunodeficiency virus in unowned free-roaming cats,” JAVMA, Vol 220, No. 5, March 1, 2002
 Schumacher, Erica, “Why are some shelters no longer testing all cats for FeLV and FIV?” University of Wisconsin-Madison School of Veterinary Medicine (2019): https://www.uwsheltermedicine.com/library/resources/why-are-some-shelters-no-longer-testing-all-cats-for-felv-and-fiv