What Is FIP? Feline Infectious Peritonitis (FIP) is a severe and often fatal viral disease in cats caused by a mutation of the feline coronavirus.
This illness primarily affects cats’ immune systems, leading to inflammation in the abdomen, chest, or other organs.
Understanding FIP is crucial for cat owners, as early detection and management can significantly impact a cat’s quality of life.
Understanding FIP: Causes and Transmission
Feline Infectious Peritonitis (FIP) is caused by a mutation of the feline enteric coronavirus (FECV), a common virus among cats.
While many cats may carry this mild coronavirus without issue, only a small percentage experience a mutation that leads to FIP, where the virus attacks white blood cells, triggering widespread inflammation.
Factors like genetics, stress, and the immune system may influence whether the virus mutates, though the exact cause remains unclear.
FIP itself is not contagious, but the coronavirus that can mutate into FIP spreads easily through saliva, feces, and close contact, particularly in multi-cat environments like shelters and catteries.
Preventative measures include maintaining clean litter boxes, reducing stress, and practicing good hygiene in multi-cat households.
Veterinarian Dr. Lisa Davis explains, “While exposure to feline coronavirus is common, FIP remains a rare outcome. It’s crucial for cat owners to monitor their pets for early signs of illness, especially in multi-cat environments.”
Symptoms of FIP
FIP can present in two forms: the wet (effusive) form and the dry (non-effusive) form. Both forms share some common symptoms but also exhibit unique characteristics. Symptoms can vary greatly depending on the form and which organs are affected.
- Loss of Appetite and Weight Loss: Cats affected by FIP often experience a noticeable decline in appetite, leading to significant and sometimes rapid weight loss. This symptom is a key indicator of the disease’s impact on the cat’s overall health and energy levels.
- Fever Unresponsive to Antibiotics: A persistent fever is a common sign of FIP, and it often does not respond to conventional antibiotic treatments. This unresponsiveness is due to the viral nature of the illness, as antibiotics are ineffective against viruses.
- Lethargy: Cats with FIP may become unusually tired, inactive, or disinterested in their usual activities. Lethargy is a reflection of the toll the disease takes on the body, often leaving the cat with little energy to engage with its surroundings.
- Jaundice: In some cases, FIP can cause jaundice, a yellowing of the skin, gums, and eyes. This occurs when the liver is affected, leading to an accumulation of bilirubin in the blood, a pigment that turns tissues yellow.
- Wet Form Symptoms: This form is characterized by fluid accumulation in the abdomen or chest, leading to swelling or difficulty breathing. It progresses rapidly and is often fatal.
- Dry Form Symptoms: The dry form affects specific organs like the liver, kidneys, or eyes, causing inflammation without fluid buildup. Neurological symptoms, such as seizures or difficulty walking, may also occur.

