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Feline infectious peritonitis

Feline infectious peritonitis (FIP) is a serious and often fatal viral disease affecting cats, especially young ones. It results from the mutation of a usually harmless feline coronavirus into an aggressive form. It exists in two main forms...

What is it?

Feline infectious peritonitis (FIP) is a serious and often fatal viral disease affecting cats, especially young ones. It results from the mutation of a usually harmless feline coronavirus into an aggressive form. It exists in two main forms, wet (with fluid effusion) and dry.

FIP is caused by a mutation of the feline coronavirus (FCoV), an intestinal virus that is usually harmless, which becomes able to infect immune cells and spread throughout the body. This mutation only occurs in some cats infected with the coronavirus.

Kittens and young cats under two years old are most at risk, as are cats living in groups, shelters or catteries. Stress, a weakened immune system and certain genetic predispositions also favor the onset of the disease.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Common signs include persistent fever, loss of appetite, weight loss and lethargy. In the wet form, abdominal swelling occurs due to fluid accumulation. In the dry form, neurological, ocular disorders or nodules in various organs may appear.

When to consult without delay

This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.

Transmission

The feline coronavirus is mainly transmitted through the fecal-oral route, notably via litter boxes shared between several cats. FIP itself, resulting from an internal mutation within the cat, is not considered directly contagious from one cat to another.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

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When faced with suggestive symptoms such as persistent fever, abdominal swelling or weight loss, it is essential to consult a veterinarian quickly for professional advice. Only a veterinarian can guide appropriate examinations and offer suitable care.

Prevention

Good litter box hygiene and limited crowding among cats reduce the spread of feline coronavirus. Avoiding feline overcrowding and limiting stress in multi-cat households also help reduce the risk. Regular veterinary follow-up remains recommended.

References

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 08 August 2026

AT A GLANCE

AgentVirus
SpeciesCat
VaccineNo
Transmissible to humansNo

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Affected species

Cat

This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.

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