Feline immunodeficiency virus (FIV, "feline AIDS") is a retrovirus affecting domestic cats as well as wild cats including lions, tigers, jaguars, leopards, panthers, and bobcats. It is not infectious to people or other species of animals. It is found throughout the world, with a high incidence in some areas.
The virus is shed in saliva and must breach the skin barrier to infect a new cat. Thus it is primarily passed from an infected to and unexposed cat through bite wounds. Thus highest risk for FIV is found in intact male cats that roam freely outdoors. It can also be spread through blood transfusions. Casual contact, insects, fomites (objects - including toys, food bowels, bedding) breeding, queening (giving birth), and nursing have not been implicated in transmission of FIV.
There are several stages of infection, classified as:
Stage 1 - Acute Primary Phase of Infection:
This begins 4-6 weeks after exposure; the effects are transient and often unnoticed. The symptoms include a fever, low numbers in infection fighting cells, enlarged lymph nodes, blood infections, anemia, diarrhea, bone marrow disease, and skin disease.
Stage 2 - Asymptomatic Latent Phase of Infection:
This is a period of up to several years, during which time no problems related to FIV are shown.
Stage 3 - Chronic Terminal Phase of Infection:
This is the phase during which problems related to acquired immunodeficiency develop. Chronic, recurrent opportunistic infections that progressively worsen over a period of months to years occur and can manifest as the following syndromes:
general weight loss and debilitation
recurrent fevers
enlarged lymph nodes
chronic recurrent bacterial infections affecting the mouth, respiratory system, intestinal system, skin , and urinary tract viral infections including calicivirus and herpes virus(cause upper respiratory infections)
fungal infections
rickettsial and chlamydia infections
protozoal infections including toxoplasmosis, giardia, Coccidia, cryptosporidia
Neoplasia (cancer) especially lymphoid and myeloproliferative (bone marrow) tumors
Treatment is aimed at treating infections and supportive therapy. It is important to reduce exposure to infectious agents and vaccinate to reduce the incidence of other viral infections. Any sign of illness should be dealt with promptly. There is no cure for FIV at this time, although human AIDS research may provide treatment options in the future.
There is no vaccination available to prevent FIV. The only control measure consists of avoiding the opportunity for an unexposed cat to fight with an infected cat. Diagnosis is made by blood testing high risk or symptomatic cats. Owners of FIV positive cats are instructed to keep their cat indoors or supervised to prevent the spread of this virus to unaffected cats.
The life span of infected cats is variable. Within 6 months of diagnosis an average of 15% of infected cats will die. Many cats will live several years and some will live a normal life span and die of unrelated causes.
An experimental treatment that has shown good results in cats with another retroviral disease (feline leukemia) is low dose orally administered alpha interferon. This is an antiviral protein that has potent immunomodulating and antiproliferative capacities. Although limited studies have been carried out on FIV positive cats, this treatment has been found to have positive results. It is given orally once a day for alternate weeks (ie on one week, off one week). There are no known side effects to this treatment.
