top of page

Feline Immunodeficiency Virus (FIV) - Feline AIDS

Updated: Feb 24, 2021

What is Feline Immunodeficiency Virus (Feline AIDS)?

Domestic Cat

Feline Immunodeficiency Virus, or FIV, is a slow, and long-acting virus exceedingly similar to the Human Immunodeficiency Virus, or HIV, in humans. It has been identified in both domestic and wild cats.

Examples of wild cats

Despite the virus taking years for clinical signs to appear in a cat with FIV, the cats usually have suppressed immune systems. FIV-infected cats are prone to other types of infections that affect other parts of the body, including the gums, mouth, digestive tract, urinary tract, and skin. They also have a heightened risk of developing certain types of blood cancers. Once any of these symptoms are noticed in a cat, veterinary attention should be sort.

How is Feline Immunodeficiency Virus (Feline AIDS) spread?

A kitten biting another

The Feline Immunodeficiency Virus (Feline AIDS) is shed in the saliva, and the virus is spread from cat to cat, primarily by biting. The Cats that roam outdoors, male cats, and older cats are at the greatest risk of infection. FIV infection is uncommon in closed purebred catteries.

Kittens suckling

Rarely, kittens get the infection from their mothers, usually during passage through the birth canal or when the newborn kittens ingest infected milk. The Feline Immunodeficiency Virus (Feline AIDS) not majorly spread through sexual contact [4].

What are the clinical signs of Feline Immunodeficiency Virus (Feline AIDS)?


Once a cat is infected, there is transient fever, enlarged lymph nodes, and reduced white blood cells. Majority of cats recover and appear clinically normal for many months or years before progressive immunodeficiency develops. The virus targets lymphocytes, leading to a gradual loss of CD4+ helper T cells, which causes widespread immunodeficiency [5]. The following are the clinical signs of a cat suffering from Feline Immunodeficiency Virus (Feline AIDS):-

  1. Weight loss

  2. Conjunctivitis (eye inflammation)

  3. Enlarged lymph nodes

  4. Dental disease (Inflammation of the gums - gingivitis)

  5. Inflammation of the mouth (Stomatitis)

  6. Chronic or recurrent infections of skin, eyes and nose (recurrent discharges, Sneezing), urinary bladder and upper respiratory tract

  7. Persistent diarrhoea

  8. Non-healing wounds

  9. Loss of, or, poor appetite

  10. Unthrifty (poor hair-coat condition)

  11. Persistent Fever

  12. Seizures, behaviour changes, and other neurological disorders.

How is Feline Immunodeficiency Virus (FIV) diagnosed?

Medical Laboratory

Diagnosis of FIV infection is by examination of blood samples for the presence of antibodies to the FIV virus. FIV antibodies are detected using a number of techniques, which include:-

  1. Enzyme-linked immunosorbent assay (ELISA),

  2. Western blot, and

  3. Immunofluorescence (IFA) assays.

These techniques are dependent upon the host cat mounting an immune response to the FIV virus.

How is Feline Immunodeficiency Virus (FIV) Treated?

Kitten with FIV

There is currently no definitive cure for FIV. However, cats infected with FIV can live ostensibly normal lives for years if managed appropriately. Once an FIV infected cat experiences one or more severe illnesses as a result of infection, or if persistent fever and weight loss are present, the prognosis is generally less favourable.

Most therapy is symptomatic and supportive. Usually, antibiotics are used for 3 weeks to control secondary bacterial infections.

Even though some antiviral drugs have been used in cats with FIV, there is no definitive evidence that they prolong their lives. The development of effective treatment options for FIV is the subject of significant research.

How is Feline Immunodeficiency Virus (FIV) Controlled?


a) Environmental Control

  • Prevent contact of uninfected cats with infected cats (thus, cats kept permanently indoors have no opportunity to become infected).

  • Testing is vital to establish which cats are infected and which are not.

  • Cat breeders should insist on FIV-negative status before accepting outside queens or stud cats.

  • Since indirect transmission does not occur, FIV-infected cats can be safely boarded in the veterinary surgery or boarding cattery with no fear of transmission to other cats.

b) Vaccination

c) Other countermeasures

  • Keep FIV-positive cats indoors so they are not a risk to other outdoor cats and so the FIV-positive cat will not be exposed to pathogens carried by other cats.

  • FIV-infected cats should be spayed/neutered and should be confined indoors to prevent the spread of FIV infection to other cats in the neighbourhood and to reduce their exposure to infectious agents carried by other animals.

  • They should be fed nutritionally complete and balanced diets, and uncooked food, such as raw meat and eggs, and unpasteurized dairy products should be avoided to minimize the risk of food-borne bacterial and parasitic infections.

  • Wellness visits for FIV-infected cats should be scheduled at least every six months.

Are there any human health concerns?


As much as Feline Immunodeficiency Virus (Feline AIDS) is similar to the human immunodeficiency virus (HIV), causing a feline disease that is similar to AIDS (acquired immune deficiency syndrome) in humans, it is a highly species-specific virus that infects only felines. Evidently, FIV has not been demonstrated to infect or cause disease in humans [7].



[1] W. Cong, Q. F. Meng, R. Blaga, I. Villena, X. Zhu and A. Qian, “Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukaemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.,” Parasitology Research, vol. 115, p. 217–223, 2016.

[2] M. J. Hosie, D. Addie, S. Belák, C. Boucraut-Baralon, H. Egberink, F. T. T. Gruffydd-Jones, K. Hartmann, A. Lloret, H. Lutz, F. Marsilio, M. G. Pennisi, A. D. Radford, E. Thiry, U. Truyen and M. C. Horzinek, “Feline immunodeficiency. ABCD guidelines on prevention and management,” Journal of Feline Medicine & Surgery, vol. 11, no. 7, pp. 575-84, July 2009.

[3] N. Tozon, M. Pistello and A. Poli, “Feline Immunodeficiency Virus (FIV) Infection in Cats: A Possible Cause of Renal Pathological Changes,” in Immunodeficiency, K. Metodiev, Ed., 2012.

[4] L. L. O'Neil, M. J. Burkhard and E. A. Hoover, “Frequent perinatal transmission of feline immunodeficiency virus by chronically infected cats.,” Journal of Virology, vol. 70, no. 5, pp. 2894-2901, May 1996.

[5] I. Tizard, “Feline Immunodeficiency Virus (FIV),” in Merck Veterinary Manual, 11th, Ed., 2016.

[6] A. L. Litster, “Transmission of the feline immunodeficiency virus (FIV) among cohabiting cats in two cat rescue shelters,” The Veterinary Journal, vol. 201, no. 2, pp. 184-188, August 2014.

[7] Cornell Feline Health Center, College of Veterinary Medicine, Cornell University, “Feline immunodeficiency virus,”, June 2019. [Online]. Available: [Accessed 9 January 2021].

151 views0 comments

Recent Posts

See All


bottom of page