Feline Immunodeficiency Virus (FIV)
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Prevent bite transmissionPeaceful household contact is low risk; prevent fighting and roaming rather than routinely isolating compatible cats.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Feline immunodeficiency virus, or FIV, is a retrovirus that gradually affects immune function. Transmission occurs primarily through deep bite wounds, making intact or roaming cats involved in territorial fighting the highest-risk group. Casual household contact, shared bowls and mutual grooming are much less efficient routes of transmission.
Many infected cats remain clinically healthy for years. Over time, reduced immune function can make some cats more susceptible to chronic oral disease, skin or respiratory infections, weight loss and other illnesses.
FIV infection produces an antibody response, but maternal antibodies can persist temporarily in kittens and previous vaccination can also complicate interpretation. Infection status may therefore be uncertain at a single time point in a young or previously vaccinated cat. Viral exposure, immune response and clinical illness remain distinct: a cat can carry the virus for years while outwardly healthy, whereas another may develop secondary disease as immune function declines.
FIV is species-specific and is not a human health risk. Infected cats can often live long, comfortable lives, particularly when kept indoors, desexed and given prompt veterinary care. The disease is managed by reducing exposure to other infections and treating health problems early rather than by attempting to eradicate the virus.
Prevention centres on reducing fighting and bite exposure.
Unlike FeLV, ordinary peaceful cohabitation is not the main transmission concern. The virus is adapted to spread through deep inoculating bites, which is why reducing roaming and fighting has such a strong preventive effect. This difference is important when deciding whether an FIV-positive cat can safely remain with familiar, non-aggressive companions.
A positive result in an adult cat may need confirmation when risk is low or the result is unexpected. Conversely, a previously negative roaming cat can become infected after a bite. Early identification allows the household to reduce transmission risk and establish a baseline for weight, oral health and blood results.
Screening & Early Detection
FIV testing is recommended for cats with unknown status, cats entering a new household, those with a history of roaming or fighting and cats with illnesses compatible with immune dysfunction. Testing is also appropriate after a significant bite exposure, but timing matters because antibodies may not be detectable immediately.
Most screening tests detect antibodies. Young kittens born to infected queens can test positive from maternal antibodies without being infected themselves, so repeat testing after those antibodies wane is important.
Vaccination history must be considered where FIV vaccine has been used, because some antibody tests cannot distinguish vaccination from natural infection. PCR or other laboratory methods can assist in selected cases, although no test is perfect in every situation.
There is no need to repeatedly test a stable, strictly indoor FIV-negative cat without new exposure.
FIV does not cause one single set of symptoms, and a positive test does not mean a cat is currently sick. Keeping cats indoors or in secure enclosures, desexing and testing new cats before introductions are more reliable strategies than assuming all social contact between cats is equally dangerous.
Treatment & Management
FIV itself is not usually treated with a single curative medication. Management focuses on maintaining general health and treating secondary disease promptly. Infected cats are ideally kept indoors or securely contained to reduce exposure to pathogens, prevent fighting and avoid transmitting the virus through bites.
Regular veterinary checks monitor weight, mouth and gums, skin, lymph nodes and any recurrent infections. Dental disease can be particularly important and should not be allowed to progress untreated. Vaccination and parasite prevention are individualised according to lifestyle and immune status rather than stopped automatically because of FIV.
When infection occurs, treatment is based on the organism and site involved. Antibiotics, antifungals or other therapies are used when indicated. Persistent fever, weight loss or lymph-node enlargement deserves investigation for concurrent disease rather than being attributed vaguely to FIV.
Stable FIV-positive cats can often live for many years. They do not necessarily need to be isolated from compatible household cats if fighting is absent, although introductions should be managed carefully. The practical goals are preventing bite transmission, maintaining a healthy body condition and identifying secondary disease early. A positive FIV result alone is not a reason for euthanasia.
Breeds or species affected
Abyssinian
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American Bobtail
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American Curl
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American Shorthair
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American Wirehair
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Arabian Mau
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Aegean
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Australian Mist
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Balinese
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Bengal
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Birman
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Bombay
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British Longhair
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British Shorthair
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Burmese
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Burmilla
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Chartreux
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Chausie
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Colorpoint Shorthair
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Cornish Rex
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Cymric
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Devon Rex
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Domestic Longhair
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Domestic Medium Hair
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Domestic Shorthair
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Donskoy
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Egyptian Mau
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European Shorthair
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Exotic Shorthair
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Havana Brown
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Highlander
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Himalayan
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Japanese Bobtail
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Khao Manee
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Korat
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Kurilian Bobtail
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LaPerm
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Lykoi
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Maine Coon
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Manx
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Minuet
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Minskin
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Munchkin
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Nebelung
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Norwegian Forest Cat
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Ocicat
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Oriental Longhair
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Oriental Shorthair
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Persian
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Peterbald
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Pixiebob
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RagaMuffin
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Ragdoll
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Russian Blue
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Savannah
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Scottish Fold
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Scottish Straight
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Selkirk Rex
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Siamese
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Siberian
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Singapura
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Snowshoe
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Somali
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Sphynx
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Thai
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Tonkinese
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Toybob
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Toyger
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Turkish Angora
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Turkish Van
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Bambino
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Cheetoh
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Dwelf
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Elf Cat
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Genetta
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Kinkalow
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Lambkin
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Serengeti
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Skookum
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Ukrainian Levkoy
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