Feline immunodeficiency virus disease in Cats (Felis) | Vetlexicon
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Feline immunodeficiency virus disease

ISSN 2398-2950


  • Cause: feline immunodeficiency virus (FIV) Feline immunodeficiency virus.
  • Signs: primary disease (lymphadenopathy, systemic illness); secondary disease (immunodeficiency diseases), eg chronic stomatitis, diarrhea, skin disease and opportunistic infections.
  • Diagnosis: ELISA Enzyme linked immunosorbent assay (ELISA), rapid immunomigration, Western blot, virus isolation.
  • Treatment: drugs for secondary illnesses, eg antibiotics; short-term corticosteroids, specific anti-retroviral drugs rarely used.
  • Prognosis: depends on response of opportunistic and secondary diseases to treatment. Often quite good in short to medium-term.
    Print off the Owner factsheet on FIV Feline Immunodeficiency Virus (FIV) to give to your client.

Geographic incidence

  • Some variation in prevalence of infection, especially from country to country.

Age predisposition

  • Older cats more likely to be infected and to show clinical signs.

Breed/Species predisposition

  • No breed predisposition.

Cost considerations

  • Specific anti-retroviral treatment, eg AZT, is expensive.



  • FIV - species specific retrovirus; has many similarities to HIV but poses no public health risk.

Predisposing factors


  • Older male cats more likely to be infected.


  • FeLV Feline leukemia virus disease - primary disease caused by FIV is worse if cat already infected with FeLV. No statistical link between prevalence of the two infections suggests that they act independently.


  • Infection with virus   →   viremia   →   lymphadenopathy, lymphopenia, neutrophilia, followed by a quiescent phase and then a steady decline in T helper cells (CD4+)   →   immunodeficiency.


  • Once infected, cats do not eliminate virus.
  • FIV positive, cats can live, in apparent good health, for years.


  • Virus spread by biting, also possibly in utero.
  • More commonly diagnosed in sick cats than healthy.


Presenting problems

  • Pyrexia.
  • Lymphadenopathy.
  • Opportunistic infections.

Client history

  • Chronic diarrhea.
  • Chronic skin disease.
  • Chronic upper respiratory tract disease.
  • Gingivitis.

Clinical signs

Primary disease

  • Pyrexia.
  • Lymphadenopathy.
  • Lymphopenia.
  • Neurological disorders.
  • Wasting.

Secondary disease

Diagnostic investigation


Confirmation of diagnosis

Discriminatory diagnostic features

  • Signs.

Definitive diagnostic features

  • Serology.
  • Viral isolation.

Differential diagnosis

  • Other causes of immunosuppression.
  • Other causes of leukopenia.
  • Other causes of lymphadenopathy.


Initial symptomatic treatment

  • Drugs to limit virus replication, eg AZT can produce short-term remissions.
  • Side-effects are common and potentially serious.
  • Expensive.
  • Antibiotics Therapeutics: antimicrobial drug and other specific treatments for secondary illnesses.
  • Corticosteroids Prednisolone 0.2 mg/kg increasing slowly to 1 mg/kg SID in short term.
    Do not immunosuppress cat with long-term steroid therapy.



  • No commercially available vaccine.

Group eradication

  • Testing for FIV is critical to prevent spread of virus.
  • Test all cats in household.
  • Remove all positive cats.
  • Quarantine negative cats, disinfect premises, then re-test in 12 weeks.
  • Test all new cats before entry to household.
  • Re-test annually.



  • Cats do not recover from infection.
  • Positive cats can live for years.

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Little S, Levy J, Hartmann K, Hofmann-Lehmann R, Hosie M, Olah G, Denis K S (2020) 2020 AAFP Feline Retrovirus Testing and Management Guidelines. J Feline Med Surg 1, 5-30 (Full Article).
  • Harrus S, Klement E, Aroch I et al (2002) Retrospective study of 46 cases of feline haemobartonellosis in Israel and their relationships with FeLV and FIV infections. Vet Rec 151 (3), 82-85 PubMed.
  • Hartmann K, Werner R M, Egberink H et al (2001) Comparison of six in-house tests for the rapid diagnosis of feline immunodeficiency and feline leukaemia virus infections. Vet Rec 149 (11), 317-320 PubMed.
  • Lappin M R (2000) Feline infectious uveitis. J Feline Med and Surg (3), 159-163 PubMed.
  • Hughes M S, Ball N W, Love D N et al (1999) Disseminated Mycobacterium genavensen infection in a FIV-positive cat. J Feline Med and Surg (1), 23-29 PubMed.
  • Heider H J, Pox C, Loesenbeck G & Egberink H (1998) Ophthalmological findings in association with different virus infections in the cat. JSAP (2), 35-42 VetMedResource.
  • Nowotny N, Uthman A, Haas O A et al (1995) Is it possible to catch leukaemia from a cat? The Lancet 346 (8969), 252-253 PubMed.

Other sources of information

  • Hopper C D, Sparkes A H, Harbour D A (1994) Feline immunodeficiency virus. In: Feline Medicine and Therapeutics.2nd Edn. Ed Chandler E A, Gaskell C J, Gaskell R M. Blackwell Science, Oxford OX2 OEL, UK. pp 488-505.
  • McCaw D L (1994) Advances in therapy for retroviral infections. In: Consultations in Feline Internal Medicine 2. Ed: August J R pp 21-25.
  • Shelton G H (1994) Management of the feline immunodeficiency virus-positive patient. In: Consultations in Feline Internal Medicine 2. Ed: August J R. pp 27-31.