FIV & FeLV
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As cat owners, we all want to keep our feline companions healthy and safe. Two of the most important infectious diseases to understand are Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV). Although both are retroviruses and both affect the immune system, they behave very differently. Knowing how they spread, what they do, and how to manage them can help you make the best decisions for your cat.
What Is FIV?
Feline Immunodeficiency Virus is often compared to HIV in humans, but it is important to note that FIV only affects cats. It cannot infect people or other animals.
How FIV Spreads
FIV spreads mainly through bite wounds, meaning it is most common in outdoor or aggressive territorial cats. Casual contact—sharing bowls, grooming, or sleeping together—very rarely transmits the virus.
What FIV Does to the Body
FIV causes a slow, progressive weakening of the immune system. Many infected cats live for years without problems, especially if kept indoors and given prompt veterinary care when infections occur.
Signs to Look Out For
Symptoms often appear later in life and may include:
- Recurrent infections
- Intermittent fever
- Chronic gingivitis or stomatitis
- Weight loss
- Poor coat quality
- Enlarged lymph nodes
- Lethargy
- Increased healing time of wounds or fractures
Managing a Cat With FIV
There is no cure, but many FIV-positive cats live long, comfortable lives. Key management includes:
- Keeping them indoors
- Routine veterinary check-ups
- Good nutrition
- Fast treatment of any infections
- Regular dental care
With the right care, an FIV-positive cat can live just as happily as any other.

What Is FeLV?
Feline Leukaemia Virus is generally more serious and more contagious than FIV. In some cats, it may cause life-limiting disease.
How FeLV Spreads
FeLV spreads through close, friendly contact, making it a risk in multi-cat households, especially where cats share bowls, beds, toys, or groom each other. It can also pass from mother to kittens.
Because it spreads so easily, FeLV is much more dangerous than FIV.
How FeLV Affects Cats
FeLV attacks the immune system but can also cause:
- Anaemia
- Lymphoma or leukaemia
- Chronic infections
- Poor growth in kittens
- Reproductive problems
- Neurological problems
Some cats develop a regressive infection, meaning the virus becomes dormant and they may live a pretty normal life. Others develop progressive infection, where the virus remains active and leads to more illness.
Signs of FeLV
Common symptoms include:
- Weight loss
- Pale gums
- Recurrent respiratory infections
- Fever
- Enlarged lymph nodes
- Lethargy
- Poor appetite
Managing FeLV-Positive Cats
There is no cure, but supportive care can offer good quality of life. Management includes:
- Keeping them indoors, especially to prevent spread
- Supportive treatment for anaemia or infections
- Monitoring for lymphoma or other complications
- High-quality nutrition and stress avoidance
FeLV-positive cats can enjoy months to years of good life with proper care.
Cats that are infected by both viruses are further compromised.

Both viruses affect the immune system so to manage cats successfully and prevent problems, immune support is pivotal. This can be done in a few natural ways:
- Herbal supplement – Echinacea, Astragalus, Ginseng, Reishi mushrooms, Shiitake mushrooms and Cordyceps fungi
- Chinese Herbal Formulae are very effective in treating the specific symptoms shown by the individual
- Livewave patches – Glutathione, X39
Testing for FIV and FeLV
Most veterinary clinics use combination tests that check for:
- FIV antibodies, and
- FeLV antigen
Results are available in 10 minutes which makes it very convenient in private practice.
Kittens under three months may test false-positive for FIV due to maternal antibodies, so confirmatory testing is recommended.
Most Welfares around the world tend to euthanaze individuals that test positive for one or both viruses. This is an attempt to reduce the spreading and eradicate the diseases. The task is, however, monumental. If cats can be contained and managed, I believe that apparently healthy individuals can be given a chance at life.
Preventing FIV and FeLV
The good news is that both viruses are largely preventable:
- Keep cats indoors or supervise outdoor time, if possible
- Neuter early to reduce roaming and fighting
- Test all new cats before introducing them into a household
- Vaccinate at-risk cats against FeLV

FIV and FeLV sound frightening, but with early testing, good management, and sensible prevention, many cats can live long, happy lives—even those who test positive. The key is knowledge, vigilance, and strong partnerships with your veterinarian.