Why You Need to Understand Feline Immunodeficiency Virus (FIV) (2023)

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Why You Need to Understand Feline Immunodeficiency Virus (FIV) (1)

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Feline immunodeficiency virus (FIV) is a disease that every cat owner should be aware of. It's especially important if you're thinking about bringing home a new feline friend. Testing new cats allows you to make informed decisions about adding the new cat to your household and the best care for that cat over the course of his life.

(Video) What You Need to Know About Feline Immunodeficiency Virus (FIV)?

What Is Feline Immunodeficiency Virus (FIV)?

How do cats get FIV? The vast majority of cats with FIV get it from being bitten by an infected cat. The virus takes up residence in the cat's lymph nodes and T-lymphocytes, spreading throughout the body. As the name suggests, the virus damages the cat's immune system and weakens it, making the cat susceptible to other infections and diseases.

Feline immunodeficiency virus works very similarly to human immunodeficiency virus. FIV itself will not kill your cat, but it does put him at increased risk for other conditions. It's these secondary infections and illnesses that cause the cat discomfort and will eventually lead to death. The chronic illness in end-stage FIV infections is sometimes referred to as feline AIDS.

Signs and Symptoms of FIV in Cats

Feline immunodeficiency virus symptoms vary depending on what secondary infection has taken advantage of the affected cat's weakened immune system.

Common symptoms of FIV in cats include:

  • Enlarged lymph nodes
  • Fever
  • Weight loss
  • Poor appetite
  • Poor haircoat and disheveled appearance
  • Diarrhea
  • Conjunctivitis (irritation of the eyes)
  • Inflammation in the mouth
  • Non-healing wounds
  • Sneezing
  • Chronic urinary, ear, or upper respiratory infections

Some cats may also show behavioral changes or other neurologic abnormalities, including seizures.

As you can see, there are no specific symptoms of FIV in cats that do not overlap with other conditions. Any cat with recurring infections that respond to treatment but then return should be suspected of having FIV, especially if he goes outside or has recently been bitten by another cat.

(Video) Dr. Becker Discusses Feline Immunodeficiency Virus (FIV)

Testing Cats for FIV

Thankfully, testing for FIV can be done with a simple blood test. Many clinics and hospitals have in-house tests that test for both FIV and feline leukemia. Several different options are available, but the most common FIV test for cats is an enzyme-linked immunosorbent assay, or ELISA, which checks for antibodies to FIV present in the cat's blood.

When a cat is infected with FIV, his immune system will produce antibodies to combat the virus. These antibodies are what the tests check for. Adult cats who have not been exposed to FIV will not have antibodies.

No test is perfect, so if your cat does test positive for FIV, it is recommended to send out a blood sample for a second test to confirm the results. As well as antibody tests, it is also possible to do a polymerase chain reaction (PCR), which detects actual viral DNA present in the blood. The accuracy of PCR testing for FIV varies, so it's important to use a reliable lab.

It is possible to get a false negative result if the cat is tested too soon after infection. It typically takes eight to 12 weeks for antibody levels to become detectable. If your cat has been bitten by a cat who is known to be FIV-positive or whose status is unknown, it's important to retest your cat two months after the exposure occurred. False negative results can also occur in cats with extremely late-stage FIV because their immune systems have become so suppressed that they are no longer producing antibodies. These cats will show signs of illness.

Kittens can receive antibodies for FIV from their mother's colostrum if the mother is infected with FIV. After the kitten is weaned, these antibodies gained from maternal immunity will wear off and be cleared from the body by the age of six months. The AAFP recommends that any kitten who tests positive for FIV at a young age should be retested after turning six months old or have a PCR test done to confirm whether or not the kitten actually has FIV. It's rare for kittens to contract an FIV infection from their mothers.

So, which cats should be tested? The AAFP recommends testing all cats to establish their FIV status, especially before the cat is added to a new home or admitted to a shelter. This helps to prevent spread of the disease to other cats. Cats with persistent or recurring illness should also be tested to determine if FIV is an underlying factor. Cats who have previously tested negative and have been living indoors either alone or with other cats who they get along with are at low risk for contracting FIV and do not need to be retested unless a potential exposure occurs, such as slipping out a door and coming back with a bite wound.

Feline Immunodeficiency Virus Treatment

There is no treatment to cure FIV. The goal for infected cats is to keep them asymptomatic as long as possible and to treat secondary infections as they occur.

An asymptomatic cat that is FIV-positive should be kept indoors to limit exposure to parasites and diseases, as well as to prevent him from getting into fights and passing on the disease. These cats should also receive a balanced diet appropriate for their life stage. The AAFP recommends veterinary exams twice a year to catch any signs of illness early, as well as annual blood and urine tests. Even indoor cats should be kept on parasite preventive medications year-round.

The antiviral compound zidovudine (also known as azidothymidine or AZT) is sometimes used in FIV infections to reduce the viral load. The AAFP notes that it is particularly beneficial for cats who are showing neurological signs or have inflammation in the mouth.

(Video) Understanding Feline Immunodeficiency Virus (FIV)

FIV-positive cats who are showing signs of illness will receive supportive care, including fluid therapy for hydration and electrolyte replacement, anti-inflammatory medications, and immune-enhancing medications.

Tips for keeping your FIV-positive cat healthy include:

  • Keep indoors
  • Schedule veterinary exams every six months
  • Have bloodwork and a urinalysis done each year
  • Keep up to date on all vaccines
  • Medicate for parasite prevention year-round
  • Spay or neuter to decrease roaming and fighting behaviors as well as spread to kittens
  • Monitor weight
  • Feed a balanced diet
  • Avoid raw foods due to increased risk of bacterial infection

RELATED: 10 Ways to Keep Your Cat Healthy

Is Feline Immunodeficiency Virus Contagious?

FIV only affects cats. It cannot be spread to humans or other animals. However, feline immunodeficiency virus is contagious from cat-to-cat. It is most commonly transmitted in the saliva, through a bite wound. Any cat can get it, but the cats most at risk for contracting FIV are intact male cats who roam and fight.

In rare cases, FIV can be transmitted from a mother cat to her kittens, usually before or shortly after birth. It can also be spread through infected blood, such as from a blood transfusion. It's unlikely to be spread through normal social interactions between cats, and it doesn't last long in the environment.

Vaccines for FIV have been made, but the one vaccine currently on the market is not available in the U.S. or Canada. Historically, FIV vaccines have not been 100% effective, meaning that vaccinated cats may still be at risk for contracting FIV. Vaccinated cats will also test positive on antibody tests. The AAFP does not consider this a core vaccine for cats, and does not recommend that cats receive it, but as always, vaccine decisions should be made on a case-by-case basis with your vet.


(Video) Feline Immunodeficiency Virus (FIV): What You Need to Know As Vets/Vet Students

What's the Outlook? Life Expectancy for Cats With FIV

How long do cats live with FIV? The good news is that these cats can still live full, normal lives. The AAFP Retrovirus Guidelines state, "Studies demonstrate that retrovirus infected cats, especially FIV-infected cats, may experience normal longevity with appropriate husbandry and disease management."

FIV has three stages: acute, asymptomatic, and clinical. In the acute phase, generally one to three months after exposure, the cat may have enlarged lymph nodes and run a fever as the virus establishes itself. Some cats may also have a poor appetite during this time. Most cat owners never notice that anything is amiss.

As the cat develops antibodies to the virus, he enters the asymptomatic phase. This phase can last many years. The cat will appear healthy and normal, but can shed the virus in his saliva. Some cats may go through periods of illness, but then revert to apparent good health.

The clinical stage is when the immune system has declined to the point that the cat shows chronic signs of illness.

Because FIV-positive cats have a weakened immune system, they are at an increased risk for developing a wide range of infections and diseases. Even normally occurring bacteria can cause dangerous infections, and cats with FIV are five times more likely to develop cancer. Any sign of illness or infection in an FIV-positive cat should be addressed and treated promptly.

A cat does not need to be euthanized simply because he is positive for FIV. Good care and nutrition can keep him healthy for many years! As with any cat, euthanasia should be considered if illness is causing him to suffer.

Can FIV-Positive Cats Live With Other Cats?

Because FIV is a contagious disease, it is recommended to keep positive cats separate from negative cats. If you have an FIV-positive cat, adding a new cat can cause stress that makes him susceptible to illness (or the new cat could bring an illness in). If you have an FIV-negative cat and are considering adopting an FIV-positive cat, introductions must be done very slowly and cautiously to avoid fighting and exposing your original cat. If one of your current cats tests positive, all cats in the household should be tested and then ideally separated into groups to prevent infection of the healthy cats.


What do I need to know about FIV cats? ›

Feline immunodeficiency virus (FIV) is a virus specific to the cat family. It is similar to HIV (human immunodeficiency virus, the cause of AIDS in people) in that it attacks and weakens the immune system and there is no cure. FIV was first recognized in the mid-1980s and has been found in cats worldwide.

What is the role of FIV? ›

FIV Orf-A is a small polypeptide of 77 amino acids that is necessary for the production of infectious virions [42]. Orf-A localizes to the nucleus and promotes cell-cycle arrest of the infected cells at the G2 phase, a biological property that is also exhibited by the Vpr protein of primate lentiviruses [43].

How do you take care of a cat with FIV? ›

Feed a nutritionally complete and balanced diet. Avoid uncooked food, such as raw meat and eggs, and unpasteurized dairy products to minimize the risk of food-borne bacterial and parasitic infections. Monitor your cat's health and behavior very carefully – alert your veterinarian of any changes as soon as possible.

Is FIV test necessary for cats? ›

We strongly recommend testing every cat, whether an adult or kitten, for the FIV virus. Just as with FelV, this is especially important if there are other cats in the household. Ideally, kittens and new adult cats should be isolated from any other cats in the home until a negative FIV test result is achieved.

Should I worry about FIV? ›

Human health concerns

There is currently no evidence that FIV can infect or cause disease in humans.

How serious is FIV in cats? ›

Key points for FIV cats

It infects the white blood cells of the immune system, killing or damaging them. A healthy immune system is needed to fight infections and monitor for cancer in the body; so infected cats have a greater risk of disease and infection from other viruses and bacteria.

What is FIV and how is it transmitted? ›

Feline Immunodeficiency Virus (FIV) is an often misunderstood condition. FIV is a lentivirus, which means it moves very slowly, and it gradually affects a cat's immune system. It is passed from cat to cat through blood transfusions and serious, penetrating bite wounds. FIV cannot be transmitted to humans.

What happens if FIV is positive? ›

Being FIV-positive means that the cat has antibodies that have been exposed to the virus, although it can take years, if ever, before the cat develops any FIV infection and clinical signs referred to as Feline AIDS (Acquired Immunodeficiency Syndrome of Cats). If a cat has FIV, it does not necessarily have Feline AIDS.

Is FIV vaccine necessary? ›

After the initial course of vaccines, a yearly vaccination is required. For cats 6 months of age and older, it is recommended that an FIV test is performed prior to vaccination. Cats should test negative before vaccination.

Can cats live a normal life with FIV? ›

Cats with FIV can live long and healthy lives. In fact, studies over the last 10 years or so have shown that cats with FIV often live as long as otherwise healthy cats that do not have this virus. Many of these cats age normally and never show signs of FIV-related illness.

How easily can cats spread FIV? ›

Although FIV isn't easily transmitted between cats (only through deep bites and not via sharing food and other normal interaction), the risk means that a FIV positive cat should only be adopted into a single-cat household.

Do cats with FIV need to be kept indoors? ›

Cats primarily pick up the virus through fighting via bite wounds or through mating behaviour. Cats Protection recommends that FIV-positive cats are kept indoors and only allowed outside in an impenetrable garden or safe run. They should not be allowed direct contact with FIV-negative cats.

Should all cats be vaccinated for FIV? ›

FIV positive cats should be kept indoors both to limit their exposure to infections as well as to prevent spread of FIV to other cats. Any other cats in the household, if tested negative for FIV need to be vaccinated to give them the best chance of protection.

Should cats with FIV be vaccinated? ›

It has been proposed that cats with FIV infection should solely receive inactivated vaccines, if possible, out of the concern that the virus components of modified-live virus vaccines given to immunocompromised animals might regain pathogenicity [39,40,41].

Do all cats need FIV vaccine? ›

FIV is most commonly diagnosed in outdoor cats, and once a cat is diagnosed as FIV-positive, they remain infected for life. It seems logical that you would just need to get an FIV vaccine to protect your cat, but the vaccine is no longer used.

Is FIV a big deal? ›

FIV simply means a cat's immune system MAY be compromised somewhere down the road. FIV is a lentivirus, which is very slow acting and usually won't affect a cat for 7 to 10 years. Most FIV cats live long, healthy, normal lives with no symptoms at all. FIV cats need the exact same good care you give to ANY cat.

Is FIV a death sentence for cats? ›

FIV is a feline-only virus that cannot be transmitted to humans. Cats who test positive for FIV can live for many years without serious symptoms. A positive FIV test result SHOULD NOT be a death sentence.

Can cats pass FIV to humans? ›

There is absolutely no evidence that any person has ever been infected with FIV.

What does FIV mean in cats? ›

“FIV” stands for “feline immunodeficiency virus” just as “HIV” stands for “human immunodeficiency virus.” In fact, these two viruses are closely related and much of the general information that has become common knowledge for HIV also holds true for FIV.

Can FIV be transmitted by touch? ›

It is very rare for cats to get FIV from just being around infected cats, from sharing food bowls, or from a person touching a FIV-positive cat and then touching a FIV-negative cat.

Where does FIV come from? ›

FIV in domestic cats most likely originated with African lions, much like HIV-2 may have originated from simian immunodeficiency virus, or SIV, in African monkeys. Like SIV in monkeys, FIV lentiviruses do not cause disease in African cats.

Can FIV be transmitted through clothes? ›

FIV is transmitted via saliva between cats that fight and bite their competition. Mothers can pass it onto their kittens. It cannot be transmitted when holding, petting, or cuddling a FIV-positive cat, and the virus cannot live on surfaces or clothing.

Can FIV cats live with non FIV cats? ›

Mixing FIV+ and FIV- Kitties in the Household

Cat lovers should be happy to learn that FIV+ cats can live in the same household with non-infected cats. According to The Cat Network, FIV does not spread to non-infected cats if they share water bowls, food bowls, litter pans, or grooming tools with an FIV+ cat.

Is FIV worse than feline leukemia? ›

Feline Leukemia (FeLV) is much more devastating than FIV. This is because FeLV typically results in cancer (e.g., lymphoma), leukemia (e.g., cancer of the bone marrow or circulating white and red blood cells), and severe bone marrow suppression (e.g. anemia) in young cats.

Can FIV be transmitted through sneezing? ›

FIV is not easily passed between cats. It can not be spread casually – like in litter boxes, water and food bowls, grooming, mock fighting, snuggling. It is not passed by scratches nor even sneezes.

Is FIV airborne? ›

Myth#1: Feline Immunodeficiency is Airborne

The feline immunodeficiency virus isn't airborne, and it can't be spread by sharing a litter box or feeding dish. It takes a major altercation for a FIV+ cat to infect a FIV negative cat.

Do cats with FIV get sick often? ›

Since cats with FIV have lowered immune systems, they're more likely to get sick from parasites, fungal infections, and other diseases. You may also see behavioral changes in your cat if they've acquired FIV. Cats who are diagnosed with FIV live a median of five years after their disease statuses have been confirmed.

Do all stray cats have FIV? ›

Compared to all other feline health threats, FIV infection is "quite common," according to Dr. Levy. "We estimate that about four percent of all feral cats in the U.S. are infected," she says.

How long do cats usually live with FIV? ›

Cats infected with FIV may live for months or years. On average, life expectancy is 5 years from the time of diagnosis depending on how active the infection is. There is a FIV vaccination given twice initially, then yearly thereafter for outside cats or cats exposed to outside cats due to the potential of cat bites.

Do cats with FIV need to stay indoors? ›

Cats primarily pick up the virus through fighting via bite wounds or through mating behaviour. Cats Protection recommends that FIV-positive cats are kept indoors and only allowed outside in an impenetrable garden or safe run. They should not be allowed direct contact with FIV-negative cats.

Is it expensive to care for a cat with FIV? ›

Treatment for the feline immunodeficiency virus is quite expensive. According to estimates, the cost range from $150 to $2,000 per treatment.

Can you touch a cat with FIV? ›

As FIV can't be transmitted to humans or other non-feline animals, an FIV positive cat is able to share his or her environment with a dog or other pet, as long as there are no other cats.

What happens if a cat with FIV bites you? ›

Feline Immunodeficiency Virus (FIV) is an often misunderstood condition. FIV is a lentivirus, which means it moves very slowly, and it gradually affects a cat's immune system. It is passed from cat to cat through blood transfusions and serious, penetrating bite wounds. FIV cannot be transmitted to humans.

How contagious is FIV in cats? ›

Woyma explains, “Unlike HIV, FIV is not typically spread through sexual contact and also very rarely transmitted from a mother cat to her kittens.” FIV is also rarely transmitted through casual contact, like sharing food bowls and litter boxes, social grooming, and sneezing.

Should FIV cats be vaccinated? ›

FIV positive cats should be kept indoors both to limit their exposure to infections as well as to prevent spread of FIV to other cats. Any other cats in the household, if tested negative for FIV need to be vaccinated to give them the best chance of protection.

Can FIV be spread through water bowls? ›

The virus can also be spread from mother to kittens, and among cats that fight. It is mainly spread through saliva when cats groom each other, and when food and water bowls are shared.

How do cats catch FIV? ›

Most cases of cat FIV come through an infected cat passing it to another through a deep bite. That makes outdoor cats especially vulnerable as they may end up in a territorial dispute that leads to such an injury. A mother cat infected with the cat FIV virus can pass it to her kittens.

Why can't FIV cats go outside? ›

There are two main reasons put forward for the policy: that outside, an FIV cat would pick up infections from neighbouring cats; and that the FIV cat could spread the virus to the neighbouring cats.

Do cats with FIV need medication? ›

Medications: Anti-viral drugs (e.g., AZT) can help some cats with FIV, but treatment is usually limited to supportive care and dealing with secondary health concerns as they arise. Diet: Good nutrition is essential to maintaining optimal immune function in FIV positive cats.


1. What is Feline Immunodeficiency Virus? (FIV+ Cats and the Important Things To Know About them)
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