What is FIP?

Feline Infectious Peritonitis (FIP) can take different forms due to the complex interaction between the virus and the cat's immune system. When a cat is infected with the feline coronavirus (FCoV), most cases are either asymptomatic or result in mild gastrointestinal symptoms. Most cats are exposed to FCoV during kittenhood. However, in a small percentage of cases, typically less than 10%, the virus mutates within the cat's body, leading to the development of FIP.

The mutations in the virus allow it to evade the cat's immune system and replicate in macrophages, which are cells of the immune system. This leads to an abnormal immune response characterized by inflammation and the formation of immune complexes.

Types of FIP

The different forms of FIP result from the distribution of these immune complexes and the sites of inflammation within the body. The specific form of FIP that develops in a cat depends on factors such as the strain of the virus, the cat's immune response, and genetic predispositions. FIP is a complex and poorly understood disease, and researchers continue to study its mechanisms!

Wet FIP

Also known as effusive FIP, this form is characterized by the accumulation of fluid in body cavities such as the abdomen or chest. This fluid is rich in immune complexes and inflammatory cells. Cats with wet FIP may exhibit symptoms such as a swollen abdomen, difficulty breathing, and lethargy.

Neuro FIP

In some cases, the immune complexes and inflammation may affect the central nervous system, leading to neurological symptoms such as seizures, paralysis, and changes in behavior.

Ocular FIP

In this form, the immune complexes and inflammation affect the eyes, leading to symptoms such as uveitis (inflammation of the uvea), which can cause eye pain, redness, and vision changes.

Dry FIP

In this form, the immune complexes and inflammation primarily affect organs such as the kidneys, liver, spleen, and intestines. This can lead to symptoms such as weight loss, fever, lethargy, and loss of appetite. While there may be some fluid accumulation, it's not as pronounced as in wet FIP.