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If your cat suddenly seems lethargic and stops eating, there may be more to it.
The fear of a serious disease such as FIP in cats can be distressing for any cat owner.

FIP, Feline Infectious Peritonitis, is a complex and serious disease that occurs in wet and dry forms and whose symptoms and treatment options can vary greatly.
In this article, you will learn all about the symptoms, progression and treatment of FIP in cats, as well as preventive measures and how modern technology can help.

What is Feline Infectious Peritonitis (FIP)?

Feline infectious peritonitis, or FIP for short, is a serious and often fatal viral disease in cats. It is caused by a mutation of the feline coronavirus and mainly affects younger and immunocompromised cats. This disease is particularly insidious because it infects the white blood cells and spreads throughout the body.

Veterinary medicine distinguishes between a wet and a dry form of FIP, which manifest themselves through different symptoms. The wet form is characterized by the accumulation of fluid in body cavities, which leads to a swollen abdomen. The dry form instead causes inflammation and tissue nodules in organs such as the liver, kidneys or brain.

The cause of FIP lies in the mutation of the otherwise harmless feline coronavirus . An infection with this virus is usually mild, but in rare cases it can mutate into the dangerous form, the FIP virus. This happens especially when several cats live together in a small space and the virus is easily transmitted.

Symptoms of FIP: Wet vs. Dry Form

Feline Infectious Peritonitis (FIP) is one of the most dangerous diseases for cats and it occurs in two main forms: the wet form and the dry form. The wet form is easier to recognize because it is often accompanied by a swollen abdomen due to fluid accumulation. This fluid can also accumulate in the chest cavity and cause breathing problems . The wet form often leads to a faster progression of the disease.

The dry form of FIP is more difficult to diagnose because it can be associated with a variety of symptoms that are also found in other diseases. Symptoms include chronic fever , loss of appetite , weight loss and apathy . In addition, neurological deficits such as convulsions or paralysis and changes in the eyes can occur.

Sometimes jaundice and anemia also develop in the dry form. The symptoms can develop over a long period of time and often affect several organs, which makes diagnosis difficult. The dry form can be divided into two variants: the ocular and the neurological form, although both forms can also occur simultaneously.


Mixed forms of the two variants of FIP are also possible and can further complicate the diagnosis. These mixed forms combine symptoms of both types, leading to fluid accumulation, inflammation and tissue nodules. This can vary the course of the disease and make treatment more difficult.

Because FIP is a progressive disease, it is important to pay attention to the early signs and seek veterinary attention early . Early diagnosis and treatment can help improve the cat's quality of life and slow the progression of the disease, even if a cure is not yet possible.

Course of FIP in cats

The course of FIP in cats is often difficult to predict and can extend over weeks or months. In most cases, the disease begins with nonspecific symptoms such as fever , reduced appetite and weight loss .

Over time, more specific symptoms may appear, such as an increase in abdominal girth in the wet form or neurological abnormalities in the dry form. Affected cats may also show yellowing of the mucous membranes , which indicates liver involvement.

The course of the disease is greatly influenced by the cat's immune response . Some cats may develop a chronic form of the disease that shows symptoms for months, while other cats experience a rapid disease progression with a fatal outcome.

Diagnosis of FIP: Methods and Challenges

Diagnosing FIP presents veterinarians with major challenges, as the symptoms are often non-specific and there is no single test that can definitively detect FIP. A combination of different tests is necessary to reach a diagnosis.

Diagnostic methods include blood tests , which can indicate abnormal values ​​in the blood serum, imaging procedures such as X-rays or ultrasound to detect fluid accumulations, and the taking of tissue samples to examine inflamed tissue.

Another method is the PCR test , which can detect the presence of the feline coronavirus. However, this test cannot distinguish between a harmless coronavirus infection and the mutated, disease-causing form.

Analysis of body cavity effusions can provide clues, but is not always conclusive. RT-PCR for FIPV-specific mutations in effusion fluids offers high specificity, but is not very sensitive and does not always provide clear results.

Treatment of FIP: What is possible?

Treating FIP in cats is difficult because there is currently no cure. Therapy aims to relieve symptoms and maintain the cat's quality of life .

Traditional treatments include anti-inflammatories and immunosuppressants to modulate the immune response and reduce inflammation, but these treatments can only slow the progression of the disease, not stop it.

However, new research results show hope. A drug containing the active ingredient GS-441524 has shown promising results in studies, but is not yet available for widespread use because it has not yet been approved.

Treatment with GS-441524 is lengthy and must be administered daily for twelve weeks . Despite the challenges this treatment presents, it offers new hope for cats diagnosed with FIP.

Prevention of FIP: Vaccinations and other measures

Feline Infectious Peritonitis (FIP) is a serious disease, but there are preventative measures to minimize the risk of infection. One of the most important measures is maintaining good hygiene . This means that litter boxes must be cleaned and disinfected regularly. The cat's living area should also be kept clean and free of pathogens. In multi-cat households, it is especially important that each cat has its own litter box to reduce the risk of infection.

In addition to hygiene, stress reduction also plays a major role in preventing FIP. A strong immune system is the best protection against disease, and stress can weaken it. Therefore, you should make sure that your cat:

  • has enough rest,
  • is not in a crowded home and
  • is not exposed to frequent environmental changes. A balanced diet and a species-appropriate environment also help to strengthen your cat's immune system.

Vaccinations can also help prevent FIP, although there is no specific vaccine against FIP . However, it is possible to vaccinate against feline coronavirus, which can mutate into FIP under certain circumstances. However, the effectiveness of this vaccine is controversial and it is usually only recommended for cats that have not previously been exposed to the virus. It is important that you consult your veterinarian to create an individual prevention plan for your cat, tailored to their health condition and lifestyle.

How Flappies Smart Cat Flap Can Help Prevent FIP

Flappie offers a smart cat flap that helps minimize the risk of FIP. Because FIP can be promoted by close contact between cats and often occurs as a result of bringing prey into the home, Flappie's flap prevents cats from coming home with prey. Here are some key features :

  • Selective access control : The flap remains closed when the cat has prey such as mice or birds.
  • Prey detection by camera : Using AI technology, Flappie identifies prey and prevents them from entering.
  • Flappie App : Allows you to control the flap remotely and gives you insights into your cat's life through videos and statistics. Through these features, Flappie can help reduce the transmission of diseases that can be caused by prey, thereby reducing the risk of FIP infection .

Frequently Asked Questions

What is FIP and FIV in cats?

FIP stands for Feline Infectious Peritonitis, a serious and often fatal viral disease in cats caused by a mutation of the feline coronavirus. FIV, on the other hand, stands for Feline Immunodeficiency Virus, which is often referred to as feline AIDS because it weakens the immune system of cats, similar to HIV in humans. FIV was not mentioned in the blog post, so the focus here is on FIP, which mainly affects younger and immunocompromised cats and can manifest itself in both wet and dry forms.

Should I vaccinate my cat against FIP?

There is no specific vaccine against FIP. However, it is possible to vaccinate against feline coronavirus, which can mutate into FIP under certain circumstances. The effectiveness of this vaccine is controversial and it is usually only recommended for cats that have not previously been exposed to the virus. It is important that you consult your veterinarian to create an individual prevention plan for your cat, tailored to their health condition and lifestyle.

What does the abbreviation FIP mean?

FIP is the abbreviation for Feline Infectious Peritonitis, a serious viral disease in cats caused by a mutation of the feline coronavirus and can manifest itself in a wet and a dry form.