FIV In Cats: Feline Immunodeficiency Virus

If you're a cat owner, then you've likely heard of Feline Immunodeficiency Virus (FIV). It's a serious virus that can affect cats, and it's something that all cat owners should be aware of. In this post, we'll discuss what FIV is, how it's transmitted, and the symptoms you should look out for if your cat has contracted it. We'll also provide some advice on how to protect your feline friend from contracting FIV. So if you're curious about this serious virus, keep reading!

What is FIV in cats and how is it transmitted?

Feline immunodeficiency virus (FIV) is a serious lentivirus that infects domestic cats and attacks the cat's immune system resulting in immunosuppression. FIV infection is common and widespread throughout the world, although prevalence rates vary depending on the geographical location and population. A research study tested 1200 client-owned cats and the positivity rate of FIV in cats was 5.5%. Cats at the highest risk of infection are adult males, those with a history of bites or abscesses, and outdoor cats.

FIV in cats is most commonly transmitted through bite wounds via saliva, so it's important to be aware of this if your cat likes to fight with other cats. The infection can also occur between household cats that don't fight but this is very uncommon.

The transmission of FIV in cats from an infected queen to her kittens can occur in utero, through milk ingestion, or both. If the queen is experiencing high levels of viremia (the presence of the virus in the blood), these routes of transmission are more likely to occur. In utero transmission can lead to fetal absorption (of the virus into the fetus), abortion, and stillbirths. But sometimes not all the kittens in the litter get FIV from their mother even if she's infected; we don't know why some seem to resist it. The amount of viral load in the queen and her viremia appear to have a significant impact on transmission rates.

What are the stages of infection?

There are three stages of FIV infection in cats: the acute stage, the latent stage, and the chronic clinical stage. The acute stage occurs within the first few weeks after infection and is characterized by fever, anorexia, lethargy, and lymphadenopathy (enlarged lymph nodes).

The latent stage is asymptomatic and can last for months or years. The chronic clinical stage is characterized by a gradual decline in health, weight loss, and recurrent infections.

What are the symptoms of FIV in cats?

Although clinical signs vary greatly, the most common symptoms of FIV in cats are:

• Fever
• Lethargy
• Lymphadenopathy
• Hypersalivation and halitosis
• Anorexia
• Weight loss
• Recurrent infections

The clinical abnormalities that occur during FIV infection are more often related to opportunistic secondary infections than to the virus itself. The respiratory, neurological, and ocular systems can also be involved and symptoms reflect this. For example, FIV-infected cats may experience:

• Pneumonia
• Conjunctivitis
• Uveitis (inflammation within the eye)
• Cognitive dysfunction
• Behavioral changes
• Head pressing
• Seizures

If your cat is displaying any of these symptoms listed above, it's important to take them to your veterinarian as soon as possible for assessment and diagnosis.

How is FIV in cats diagnosed?

FIV in cats can be diagnosed through a combination of your cat's history, clinical signs, and laboratory testing. Your veterinarian will likely take a thorough history from you, including any recent changes in behavior or appetite, as well as any sick contacts your cat may have had. A physical examination will be performed and abnormalities such as fever, lymphadenopathy, weight loss, and ocular or neurological changes may be noted.

To confirm the diagnosis of FIV, your veterinarian will likely recommend one or more of the following tests:

ELISA (enzyme-linked immunosorbent assay) - this is a screening test that looks for antibodies to FIV in the blood and is the most commonly used test for FIV in cats.

PCR (polymerase chain reaction) - this test looks for FIV DNA in the blood and can be used to diagnose FIV in cats that are in the early stages of infection (before antibodies have developed).

The potential for false negatives

The vast majority of cats will develop antibodies against the disease within two months of infection, although some may take up to four months. Antibody levels can be negative early on in the course of the disease, so it is recommended that cats be retested at least two months after their last potential exposure.

The potential for false positives

Kittens may test positive for antibodies even if they have not been infected, due to maternal immunity (protective antibodies passed from mother to kitten). If a kitten tests positive, it should be retested after 6 months of age when this immunity has decreased. Vaccinated cats will also test positive on antibody kits, as there is no way to distinguish between antibodies from the vaccine and those from natural infection.

What is the treatment for FIV in cats?

There is no specific cure for FIV and once a cat is infected, it will remain infected for life. However, with proper care and management, FIV-infected cats can live long and healthy lives. Treatment is aimed at supporting the cat and preventing secondary infections.

There are anti-viral medications available such as Zidovudine and Fozivudine but these medications will not prevent viral infection or prevent viral replication. These anti-viral medications will help reduce viremia which is the amount of FIV in the blood and the progression to the clinical stage.

The supportive aspects of treatment for FIV-infected cats are supportive care and management, which include:

• Providing a nutritionally complete and balanced diet
• Keeping up with routine vaccinations and parasite control
• Regular veterinary check-ups
• Managing stress and reducing change
• Providing a clean and comfortable environment
• Reducing exposure to other cats

What is the prognosis for FIV in cats?

Many FIV-infected cats live long, healthy lives with the proper care and management. The infection usually has no symptoms for years, and one study showed that there was no difference in lifespan between infected cats in the asymptomatic phase and uninfected cats.

How can you prevent your cat from contracting FIV?

In order to keep other cats safe, as well as to minimize their exposure to infection, it is important to keep any infected cats indoors. In addition, routine parasite control should be put into place. For diet, it is best to feed a complete and balanced diet to avoid any food-borne bacterial and parasitic diseases that could come from raw diets.

Cats living in households with a stable social structure and no fighting are at low risk of transmitting the virus; however, the transmission may still occur. Keeping infected and non-infected cats separate can help limit transmission.

Vaccination against FIV

An FIV vaccine is available but its efficacy is variable when preventing infection. The FIV vaccine is not considered a core vaccination and can be saved for cats with lifestyles that put them at risk (for example, those living with housemates who have FIV, and outdoor cats that are likely to get into fights). Kittens should be vaccinated starting at 8 weeks of age and then given a booster 3-4 weeks later. Adult cats should be vaccinated annually.

Screening tests for FIV

The American Association of Feline Practitioners (AAFP) recommends screening tests in the following circumstances:

• All new cats brought into the household, including strays and adopted cats
• Any cat that is going to be introduced to an FIV-infected cat
• Any cat with a history of fighting
• Cats that are outdoors and at risk for fighting or exposure to FIV-infected saliva
• Cats showing signs of illness and compatible clinical symptoms
• Any cat that has been exposed to the virus (wait 60 days from time of exposure to test)

Frequently asked questions about FIV in cats

FIV in cats, or Feline Immunodeficiency Virus, is a serious feline infection that can eventually lead to serious health issues. The virus is most commonly transmitted through cat bites and fighting, and can also be spread through saliva and blood. FIV-infected cats should be kept indoors and separate from other cats to minimize transmission. There is no cure for FIV, but with proper care and management, many FIV-infected cats live long healthy lives. Routine vaccinations and parasite control are important preventative measures for all cat owners. If you have any further questions about FIV in cats, please speak to your veterinarian.