Dealing with Feline Infectious Peritonitis (FIP) in Cats

Feline Infectious Peritonitis (FIP) is a serious and often fatal disease affecting cats, caused by a mutation of the feline coronavirus. Understanding FIP is essential for cat owners, especially those with multiple cats, to prevent spread and ensure early intervention. Households with several cats are at greater risk as the virus can be transmitted through faeces and respiratory secretions, contaminating shared spaces. People can also inadvertently carry the virus on their hands or clothing between cats, so good hygiene helps reduce transmission risk.

The Virus Explained

The virus primarily targets cats with compromised immune systems, including young kittens with immature immunity, and older cats whose immunity may decline with age. It spreads within the cat's body via infected white blood cells. While kittens from 3 months to 3 years are most vulnerable, senior cats may also develop FIP due to weakened defences. The disease is caused by a mutation of the common feline coronavirus found in many healthy cats, which mutates in some individuals leading to FIP.

Types and Symptoms to Watch Out For

FIP manifests in two main forms with differing symptoms:

• Wet (Effusive) Form: This aggressive form causes fluid accumulation in body cavities, including the abdomen and chest.
• Dry (Non-effusive) Form: This form affects internal organs causing granulomatous inflammation without fluid build-up.

Both forms cause general signs such as dull coat, weight loss, lethargy, and depression. The wet form tends to progress rapidly with symptoms including persistent fever not responding to treatment, loss of appetite, swollen abdomen, breathing difficulties, sneezing, and nasal discharge. The dry form can lead to slow poor growth in kittens, anaemia, jaundice, fever, eye inflammation, and neurological signs like vision loss or lack of coordination.

Causes and Mutation Process

FIP occurs when a typically harmless feline coronavirus mutates within the cat’s body, especially if the immune system struggles to control it. This mutation converts a standard coronavirus infection into the much more severe FIP virus which invades and infects white blood cells. The virus may lie dormant for months before mutation and disease onset. This complex interaction explains why not all cats exposed to the coronavirus develop FIP.

Diagnosing FIP

Diagnosing FIP can be challenging due to overlapping symptoms with other diseases. Veterinary diagnosis often involves a combination of tests including:

• Complete blood count to detect white blood cell changes.
• IFA or ELISA tests to detect coronavirus antibodies.
• PCR testing to identify viral genetic material.
• Analysis of fluid samples from the abdomen or chest if present.

In complicated cases, exploratory surgery may be necessary to obtain tissue samples for definitive diagnosis.

Current Treatment Options

Treating FIP remains difficult but recent advances have transformed outlooks for some cats.

• Antiviral Medication: The revolutionary antiviral GS-441524 is now approved and has improved survival. It is administered orally or by injection over 8 to 12 weeks. This treatment is not yet universally available but represents hope for managing FIP.
• Supportive Care: Hydration via subcutaneous fluids at home, nutritional support, and drainage of chest or abdominal effusions to ease breathing are important. Pain relief helps manage discomfort as the disease progresses.
• Immune Modulation: While immune-suppressing drugs like prednisolone have been used historically to slow progression, these do not cure FIP and are less commonly used with newer antivirals.

Early veterinary intervention and close monitoring by your vet are essential to optimise treatment success and maintain your cat’s quality of life.

Living with a Cat Diagnosed with FIP

The prognosis for cats diagnosed with FIP is often guarded, especially with the wet form. Providing supportive care at home focused on comfort is key. During active disease stages, affected cats should be separated from others to reduce coronavirus spread. Cleaning and disinfecting living areas and feeding bowls regularly is crucial in multi-cat households.

While FIP remains a daunting diagnosis, ongoing research and treatments such as antiviral therapy offer new hope for many cats and their owners.

For advice on finding healthy cats or kittens, choosing responsible breeders, or adoption, always consult qualified professionals.