A cat sits in a vet office being treated for FIV

Feline Immunodeficiency Virus (FIV) Factsheet

Feline AIDS (acquired immunodeficiency syndrome) is caused by infections with Immunodeficiency Virus (FIV). It is a viral disease which affects the immune system of cats, and can be potentially fatal. It is important to have your cat vaccinated against FIV from their very first immunisations as a kitten

What is Feline Immunodeficiency Virus?

Feline Immunodeficiency Virus (FIV), sometimes referred to as feline AIDS, is a viral disease that affects a cat’s immune system. Over time, the virus weakens the body’s natural defences, making infected cats far more susceptible to infections and illness. While FIV is species-specific and cannot be passed to humans or other animals, it can be serious and potentially life-limiting for cats.

In the early stages, cats with FIV may appear completely healthy and show no obvious symptoms. As the disease progresses, however, the immune system becomes increasingly compromised and may eventually be too weak to fight off secondary infections that a healthy cat would normally overcome. These complications can significantly affect a cat’s quality of life and, in severe cases, may ultimately lead to death.

Because FIV can have long-term health consequences, prevention is key. Vaccination from a cat’s very first kitten immunisations is strongly recommended, particularly for cats that may interact with other cats or have access to the outdoors.

How to Recognise FIV: Common Signs and Symptoms

Cats are very good at hiding illness, so the signs of Feline Immunodeficiency Virus (FIV) can be subtle—particularly in the early stages. Some cats may appear healthy for months or even years after infection.

Early or initial signs may include:

  • Fever

  • Loss of appetite

  • Lethargy or reduced activity

  • Diarrhoea

  • Swollen lymph nodes

As the disease progresses and the immune system becomes increasingly compromised, more serious or recurring health issues may develop, including:

  • Weight loss

  • Poor coat condition

  • Mouth sores or gum disease

  • Eye problems

  • Chronic or recurring infections

  • Certain cancers

If your cat shows ongoing or unexplained illness, veterinary testing is essential for early diagnosis and management.

How is FIV Spread Among Cats?

FIV is primarily spread through saliva entering the bloodstream, most commonly during bite wounds from cat fights. This is why unneutered male outdoor cats are at the highest risk.

Less common transmission routes include:

  • From an infected mother to her kittens during pregnancy or via milk

  • Occasionally through mating or shared food and water bowls

While FIV is similar in disease process to Human Immunodeficiency Virus (HIV), FIV is species-specific. Humans and other animals cannot become infected with FIV.

Can FIV Be Cured?

There is currently no cure for FIV. Treatment focuses on managing symptoms and secondary infections as they arise.

With regular veterinary care, good nutrition, parasite prevention, and prompt treatment of illness, many FIV-positive cats can live comfortable, happy lives for years.

Caring for a Cat with FIV

Cats diagnosed with FIV require some additional care to protect their health and prevent the spread of the virus.

Key care recommendations include:

  • Keeping your cat indoors at all times or within a secure outdoor enclosure

  • Limiting exposure to other cats to reduce the risk of secondary infections

  • Scheduling twice-yearly veterinary check-ups

  • Providing high-quality nutrition and parasite prevention

If you have other cats:

  • Have them tested for FIV

  • Ensure FIV-negative cats are vaccinated

  • If cats live together peacefully and do not fight, the risk of transmission is low

How to Prevent FIV in Your Cat

Prevention is the most effective way to protect cats from FIV.

Key prevention strategies include:

  • Ensuring kittens receive their full vaccination schedule

    • The FIV vaccine consists of an initial course of three vaccinations, given 2–4 weeks apart

    • Followed by annual boosters for life

  • Maintaining yearly boosters regardless of your cat’s age or lifestyle

  • Keeping cats indoors or in secure outdoor play areas

  • Neutering cats to reduce roaming and fighting behaviour

Vaccination is especially important for cats with outdoor access or those living with an FIV-positive cat.

Key Points to Remember:

  • Feline Immunodeficiency Virus (FIV) is a potentially life-limiting disease that weakens a cat’s immune system

  • FIV can lead to feline AIDS over time

  • It is similar in disease process to HIV in humans, but it is not the same virus

  • Humans cannot contract FIV

  • All cats should be vaccinated against FIV if they are at risk

  • FIV-positive cats should be kept indoors to protect their health and prevent spread

 

← Back to all posts