By: Neva DeCoux, Michelle Kwok

Feline immunodeficiency virus (FIV) is a type of lentivirus ("slow virus") classified by a long incubation

period (may last as long as 6 years) that slowly develops into the disease.

It is in the same retrovirus family as feline leukemia virus (FeLV) and human immunodeficiency virus (HIV). It attacks the immune system, and as a result, the cat is

unable to fight off various infections and cancers.

Approximately 2.5% of cats in the United States are infected with FIV.

• The virus, a lentivirus, interacts with lymphocytes, changing their ability to function normally in the immune response process.

• The resulting lymphopenia, loss of memory cell function, and decrease in antibody production from T-cell stimulated lymphocytes leaves the cat open for opportunistic infection.

Retroviruses are species-specific. This means a feline retrovirus like FIV will only infect cats; a human retrovirus such as HIV will only infect humans.

Retroviruses are made up of RNA. In the host, the RNA is transcribed into DNA and incorporated into the DNA of the host’s cells.

Retroviruses are fragile, being easily inactivated by ultraviolet light, heat, detergents, and drying.

It was first discovered during the investigation of a disease outbreak in a previously healthy colony of rescue cats at UC Davis in 1986 by immunologists Janet Yamamoto and Niels Pederson

The colony had been showing similar signs to people with acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) infection.

Yamamoto started working on a vaccine for FIV at UC Davis.

Vulnerable at any age• Outdoor, free-roaming felines

are at greater risk- Male felines are 1.5 to 3 times more likely to become infected then a female feline. - Is rare in catteries

More predominant in free-roaming aggressive male cats due to transmission by bite wounds

Infects domestic cats, and can also infect wild felines including snow leopards, lions, tigers, jaguars, Florida panthers, and bobcats.

- Feline Male was diagnosed to be FIV positive.

Casual, non-aggressive contact does not appear to be an efficient route of spreading FIV.

On rare occasions infection is transmitted from an infected mother cat to her kittens, usually during passage through the birth canal or when the newborn kittens ingest infected milk

FIV transmission in utero or through the mother's milk is very rare. It could possibly occur if the queen is infected during pregnancy or while nursing the kittens.

Queens infected with FIV prior to the pregnancy usually have non-infected kittens.

The primary modes of FIV transmission are deep bite wounds and scratches,

where the infected cat's saliva enters the other cat's bloodstream.

Sexual contact is not a major means of spreading FIV.

Although FIV is a lentivirus similar to HIV (the human immunodeficiency virus) and causes a disease in cats similar to AIDS (acquired immune deficiency syndrome) in humans, it is a highly species-specific virus that infects only felines.

Poor coat condition and persistent fever with a loss of appetite are commonly seen.

Lethargy Inflammation of the gums (gingivitis) and mouth

(stomatitis) and chronic or recurrent infections of the skin, urinary bladder, and upper respiratory tract are often present.

Persistent diarrhea Slow but progressive weight loss is common, followed

by severe wasting late in the disease process. Various kinds of cancer and blood diseases are much

more common in cats infected with FIV, too. In unspayed female cats, abortion of kittens or other

reproductive failures have been noted. Some infected cats experience seizures, behavior

changes, and other neurological disorders.

• Febrile episodes• Lymphadenopathy (chronically swollen lymph nodes)• Persistent infections unresponsive to

treatment• Weight loss• Gingivitis• Ocular lesions• Slow-healing traumatic wounds• Behavior abnormalities• Chronic upper respiratory infections• Anemia

Pansystemic disease

Elisa (Enzyme-linked immunosorbent

assay) Detects anti-FIV antibodies Most common Rapid and reliable method Does not work well with very early

infection False positive is very rare Repeat test to be sure

Immunoblotting Uses anti-bodies to

detect HIV related proteins

PCR (polymerase chain reaction)

Detects the virus itself Very useful for detecting

infection in kittens born from the FIV positive mother 

Check for false positives

• ELISA test (enzyme-linked immunosorbent assay): will be positive

-It is possible to get false positive or false negatives from these results for the following reasons:

False Positive False Negative•Kittens born to FIV infected mothers may have received antibodies from their mother’s milk. This doesn’t mean that the kitten has FIV, just that it has received antibodies to FIV. Kittens that test positive should be re-tested at a later date.

•It usually takes several weeks for the antibodies for FIV to appear in the blood, if a cat is tested prior to this it will show a negative test result.

•If a cat has received the FIV vaccine the test results will show up positive.

•If the cat is in the later sages of infection it may not be producing antibodies.

• A FIV PCR (polymerase chain reaction) test is available in some commercial laboratories. PCR detects the presence of the FIV virus in the blood.

• Western blot test or IFA (Immuno-Fluorescent Antibody Test): If a cat has tested positive to FIV it is sometimes recommended to follow up with either a Western Blot Test or an IFA test.

• If your cat has tested positive to FIV but you are not sure if it has had the vaccine, or want to be sure it does/doesn't have the virus then you may be able to request a PCR (polymerase chain reaction) test, which will be able to detect the presence of FIV DNA in the blood.

• Urinalysis: elevated protein levels

• CBC (stage 3): anemia, lymphopenia, neutropenia

No treatment to eliminate the virus Depends on the proper health

management There are some anti-viral medications

but they are not 100% effective in improving the immune system

• FIV is treated symptomatically.

• Medications: -Antibiotics for secondary infections-Appetite stimulants-Corticosteroids -Immune modulatorsDental extractions with chronic gingivitis and stomatitis

• Some also require nutritional support, fluid therapy, and dental care.

It is not possible to determine how long a FIV positive feline will live, but with proper care and supportive therapy they can live a full life.

• The outlook for cats that show severe, chronic, multiple signs of disease is poor.

• If clinical signs have developed only recently and are not severe, there is a reasonable prospect of improvement with treatment, which may be maintained for some time.

• Greater than 50% of infected felines remain asymptomatic within 2 years after diagnosis

• Treatment usually consists of supportive therapy, often antibiotics, possibly coupled with antiviral therapy.

• Felines in the terminal stage of the disease survive less then one year.

• For kittens can detect maternal AB hence re-test after 6 months.

• Average life span from diagnosis to death is roughly around 5 years.

University of Bristol School of Veterinary Science Study• A range of tissues from a total of 17 cats naturally infected with

the feline immunodeficiency virus was examined histologically.• In 11 cases, chronic inflammatory lesions were present in

various tissues including, most commonly, the intestine, brain and lung. Extensive inflammation in the intestinal wall was present in seven of the cats.

• No particular bacterial organisms were demonstrated in these inflammatory lesions. A range of changes was present in the lymph nodes, including hyperplasia, atrophy or a mixed pattern. Erythrophagocytosis was a consistent feature.

• Some present with dysplastic nodes characterized by follicular atrophy (wasting away of the follicles), paracortical cell depletion, and fibrosis (excess fibrous connective tissue).

The most commonly occurring lesions (seen in 91% of infected cats) were thymic atrophy, generalized lymphoid hyperplasia, and bone marrow hyperplasia.

The second most common lesions were splenic lymphoid hyperplasia and thymic follicle formation (78–83% of cats).

A third set of miscellaneous lymphoid and mucosal lesions was confined to ≤30% of cats.

• Isolate affected cats.

• Keep unaffected cats away from feral cats.

• A vaccine for FIV currently is available - may test positive for FIV at a later date

• Spaying and neutering outdoor cats can limit exposure by decreasing aggressive behaviors.

- especially males

Cons Does not provide full

protection against all strains.

Since it is a killed virus, adjuvants are used which carry the possibility of vaccine associated sarcomas forming.

Vaccinated feline will always be FIV positive. Can be a problem if lost and placed in a shelter.

Pros Provides 82% protection

against strain A.

No blood test can differentiate between a

vaccinated cat and a truly infected FIV

positive cat.

Educate about the virus and vaccine FIV is a progressive disease FIV infected felines should be confined indoors to

prevent the spread of the virus FIV infected felines should be spayed or neutered Should be fed complete and balanced nutritional diet Uncooked food should not be fed (Ex: raw meat, eggs

and unpasteurized dairy products) Wellness visits for FIV infected felines should be

scheduled with your veterinarian at least every six months

Close monitoring of health and behavior  Test all new additions to the cat’s household.

http://www.vet.cornell.edu/fhc/brochures/fiv.htmlhttp://www.knowyourcat.info/health/fiv.htmlhttp://www.fivprognosis.org/owners.htmlhttp://www.peteducation.com/article.cfm?c=1+1316&aid=213

• Common Diseases of Companion Animals• Veterinary Technician’s Daily Reference

Guide• www.vet.cornell.edu • www.merckvetmanual.com• www.cat-world.com.au • http://gateway.nlm.nih.gov• http://fabcates.org• http://sciencedirect.com