All You Need to Know About Feline Immunodeficiency Virus (FIV) 

When it comes to feline health, an often overlooked disease that demands attention and care is the Feline Immunodeficiency Virus (FIV), a close relative of the well-known Human Immunodeficiency Virus (HIV). While not a household name, FIV poses a massive threat to our feline friends, particularly those who roam outdoors.

As an insidious viral infection, FIV quietly infiltrates a cat's immune cells and progressively compromises its natural defence mechanisms. Unlike some viral infections, FIV doesn't directly lead to fatal outcomes but causes secondary infections that exploit the cat's weakened immune system. FIV-infected cats ultimately succumb to secondary infections caused by a weakened immune system rather than due to the virus itself.  

How is FIV transmitted? 

Feline Immunodeficiency Virus (FIV) is primarily transmitted through bite wounds due to aggressive behaviour commonly associated with territorial disputes and mating activities among outdoor, intact male cats. 

The virus is present in high concentrations in the saliva of infected cats, and when an FIV-positive cat bites another cat, the virus can be introduced into the bloodstream of the bitten cat. However, unlike other infectious diseases in cats, FIV is not easily transmitted through casual social contact, such as grooming, shared food and water bowls, or urine and faeces. 

Furthermore, mother-to-kitten transmission of FIV can occur, but it is relatively uncommon. Kittens born to an FIV-positive mother may become infected during birth or through the ingestion of breast milk. 

However, not all kittens born to FIV-positive mothers will contract the virus, and this transmission tends to happen only if the FIV-positive mothers have a high viral load. Though relatively uncommon, a pregnant FIV-infected cat may miscarry or give rise to a stillborn in some extreme cases.

What are the clinical signs of FIV infection?

Feline Immunodeficiency Virus (FIV) manifests in distinct stages, and each phase has a different facet of the infection. It's crucial to note that not all cats will go through every stage, and some may remain asymptomatic throughout their infected lives.

Stage 1: The Acute Phase

During the acute phase, a cat has recently contracted FIV. At this stage, the virus enters the vital immune organs, such as lymph nodes, and through white blood cells, it disseminates to other organs, including the bone marrow, brain, and lungs.

The clinical signs may include lethargy, fever, and enlarged lymph nodes. However, some cats may exhibit no outward symptoms during this stage.

Stage 2: The Latent Phase

Following the acute phase, the infected cat enters a latent phase, usually characterised by an absence of observable symptoms. This period can persist for varying durations, ranging from months to years. Despite the absence of clinical signs, the virus quietly persists within the cat's system and prepares itself for the next stage.

Stage 3: AIDS-Related Complex (ARC) Phase

The AIDS-related complex (ARC) phase marks a critical juncture in FIV progression. At this stage, the infected cat experiences a progressive immune system compromise and becomes susceptible to various secondary infections.

These infections can manifest in various organs and lead to complications in the eyes, gums, lungs, skin, or even the development of tumours. The ARC phase often surfaces years after the initial infection, highlighting the slow and insidious nature of FIV's impact on feline health.

How is FIV diagnosed? 

Accurate diagnosis plays a significant role in managing Feline Immunodeficiency Virus (FIV); therefore, we provide an in-clinic test kit that can test for antibodies against FIV antigen. The diagnostic process involves testing for antibodies against the FIV antigen, which requires only a small blood sample from your cat. 

However, as the FIV test detects antibodies, cats previously vaccinated against FIV will test positive. To overcome this, it is recommended that cats undergo FIV testing before receiving their first vaccination. This precaution ensures that subsequent tests accurately differentiate between a naturally infected cat and one that has been vaccinated.

For kittens under 6 months old who test positive, caution is advised as maternal-advised antibodies in their blood might yield a positive result, but it doesn't necessarily indicate actual infection. Retesting is recommended after 6 months, as maternal immunity wanes, providing a clearer picture of the cat's FIV status. Persistent positivity after this age indicates the cat has encountered an FIV infection.

False negatives can occur under specific circumstances. Recent infections may yield inaccurate results as it takes time for antibodies to develop, typically around 60 days. Moreover, some cats may exhibit a delayed response and require up to 4 months to develop sufficient antibodies for detection.

In cases of end-stage disease, cats may have such low antibody levels that they fall below the test's detection threshold, which may result in false negatives.

How do I take care of an FIV-positive cat? 

Discovering that your cat is Feline Immunodeficiency Virus (FIV) positive can be pretty disheartening, but with informed care and attention, your feline companions can lead fulfilling lives despite no cure for this infection. 

While the latent (asymptomatic) phase duration remains unpredictable, it's reassuring to know that FIV-infected cats have the potential to live up to their expected lifespan with the proper care.

Keep your cats indoors

The first step in caring for FIV-positive cats is to create a safe and comfortable indoor environment, as this can reduce the risk of exposure to potential infections and minimise the chances of injury from outdoor hazards. We recommend providing stimulating toys and ensuring fun indoor activities to keep your cats engaged indoors and enhance their physical and mental well-being. 

Regular veterinary check-ups

A regular veterinary check-up is another crucial step to protect and minimise the chances of FIV-positive cats contracting other infections. These regular follow-ups will help your veterinarian monitor the cat's overall health, detect any emerging issues, and provide timely intervention.

Ensuring a nutritious diet

Ensuring a well-balanced and nutritious diet is essential for supporting the immune system of FIV-positive cats. High-quality cat food, rich in essential nutrients, can improve their overall health. Raw food should be avoided, as this will expose your cat to worms and bacterial infections.

What is Feline Leukaemia Virus (FeLV)? 

Feline Leukaemia Virus (FeLV) is a pervasive infectious disease that affects cats globally. Beyond its association with leukaemia, this virus is a multifaceted threat and causes immunosuppression and the risk of contracting secondary diseases.

While the name implies a connection to leukaemia, FeLV's impact extends far beyond this specific form of cancer. The virus targets the cat's white blood cells, which may sometimes lead to leukaemia. However, its primary mechanism lies in immunosuppression, which leaves the affected cats vulnerable to various secondary diseases.

FeLV-induced immunosuppression weakens the cat's ability to fend off infections and creates an environment for secondary diseases to flourish. Respiratory infections, dental problems, and gastrointestinal issues are among the health complications that can arise in FeLV-positive cats.

How is FeLV transmitted?  

Feline Leukaemia Virus (FeLV) is primarily transmitted through close contact between cats. The transmission commonly occurs through the following routes:

• Mutual grooming: FeLV can be transmitted when infected cats groom each other. The virus is present in saliva, and an unaffected cat may come into contact with the virus during grooming sessions.
• Shared food and water bowls: FeLV can be present in saliva, and if cats share food and water bowls, there is a risk of virus transmission. This risk factor is particularly relevant in multi-cat households or communal feeding areas.
• Bite wounds: aggressive interactions among cats, such as biting, can lead to the direct transfer of FeLV through saliva. A bite that breaks the skin makes a cat more susceptible to transmission.
• Vertical transmission (from mother to kittens): FeLV can be transmitted from an infected mother cat to her kittens during pregnancy, birth, or through the consumption of infected milk. Kittens born to FeLV-positive mothers are at an increased risk of infection.

However, FeLV is not highly contagious and does not survive for long periods in the environment. However, the risk of transmission is higher in situations where cats have prolonged, close contact, especially in multi-cat households. 

Stages of FeLV Progression

FeLV infection unfolds in three distinct stages: abortive, regressive, and progressive.

Stage 1: Abortive infection

After a cat is infected with FeLV, the virus initially reproduces in the lymphoid tissues of the oropharynx (throat). If the cat's immune system successfully eliminates the virus during this stage, it is classified as having an abortive infection. Most cats with robust immune systems fall into this category.

Stage 2: Regressive infection

If the virus is not cleared at the initial stage of entry to the body, it infects white blood cells and migrates to the bone marrow. In regressive infection, the cat's immune system attempts to control viral replication, although complete elimination is not achieved.

The virus remains in the bone marrow without active replication. Cats in this stage may appear healthy for extended periods, but the virus can reactivate, particularly after stressful events or immunosuppression.

Stage 3: Progressive infection

For cats whose immune systems cannot control or eliminate the virus, FeLV replicates extensively in lymphoid tissues, bone marrow, and epithelial tissues of salivary glands, bladder, and tear glands. Cats with progressive infections shed substantial amounts of virus in their saliva and bodily fluids. This category of cats is more prone to developing FeLV-related diseases.

Understanding these stages is crucial for assessing the potential outcomes of FeLV infection in cats. While some cats can successfully clear the virus, others may enter a state of controlled persistence, and unfortunately, a portion may experience ongoing replication, leading to increased health risks. Regular veterinary monitoring and preventive measures are critical components in managing FeLV-infected cats at each stage of the infection.

What are the clinical signs of FeLV?

Feline Leukaemia Virus (FeLV) infections can manifest in various clinical signs, with distinct presentations depending on the stage of infection.

Cats in the regressive stage may outwardly appear normal, yet the virus can reactivate, particularly during times of stress, and give rise to symptoms. On the other hand, progressive FeLV infection results in multiple health challenges, including the heightened risk of leukaemia, lymphoma, and immunosuppression, making cats susceptible to secondary infections.

Common clinical signs include fever, lethargy, weight loss, and lymph node enlargement, which warrant attention during routine monitoring. Other symptoms include respiratory infections marked by coughing and nasal discharge, oral ulcers that impact eating habits, and gastrointestinal disturbances that lead to vomiting and diarrhoea.

Recognising these clinical cues is crucial for early detection and timely intervention. Cats exhibiting these symptoms, particularly those with a history of FeLV exposure, should undergo immediate veterinary evaluation.

How is FeLV diagnosed?

FeLV can be diagnosed in the clinic with a simple blood test that detects the viral antigen (part of a virus). For regressive cats, as the viral levels in their blood fluctuate depending on whether the virus is in its dormant or reactivated stage, some regressive cats may test negative. 

However, it's essential to note that for regressive cats, whose viral levels can fluctuate depending on whether the virus is in its dormant or reactivated stage, there may be instances where these cats test negative. Therefore, it’s essential to focus on the cat's clinical history, potential exposure, and symptoms and repeat testing for accurate diagnosis, especially in cases where initial results are inconclusive. 

Regular veterinary monitoring and consultation are essential to the diagnostic process and ensuring the well-being of FeLV-infected cats. To ensure the health and well-being of your feline companions, schedule an appointment with Dr Paws Vet Care today! 

What are the treatment options for FeLV-infected cats?

Regrettably, there is currently no cure for the Feline Leukaemia Virus (FeLV); therefore, it is essential to take proactive measures in its management. A crucial step in safeguarding feline health is testing any newcomer cats before introducing them into a household. This precautionary approach allows for the early identification of FeLV-positive individuals and helps make informed decisions about their integration into a new environment.

While a definitive cure remains elusive, regular testing, preventive strategies, and close collaboration with veterinary professionals can also help minimise the impact of FeLV on feline populations. The vigilance and preventative measures are crucial for maintaining the health and well-being of individual cats and the overall feline community.