What is FIP?

FIP is caused by a mutation of the feline coronavirus (FCoV), a virus that is common in cats, especially those in multi-cat environments. Most cats exposed to feline coronavirus will never develop FIP, but in a small percentage of cases, the virus mutates inside the body and leads to FIP.

FIP is not typically contagious in its mutated form, it develops individually within the affected cat.

How is it Transmitted?

• The feline coronavirus (FCoV) is spread through:

  • Feces (litter boxes are the primary source)

  • Contaminated surfaces

  • Close contact between cats

• However, FIP itself is not directly contagious, it occurs when the virus mutates within a cat’s body.

Risk Factors

Cats more likely to develop FIP include:

• Kittens and young cats (under 2 years old)

• Cats in shelters, rescues, or multi-cat homes

• Cats under stress (rehoming, illness, overcrowding)

• Cats with weaker immune systems

Clinical Signs

FIP can appear in two main forms:

Wet (Effusive) Form

• Fluid buildup in the abdomen or chest

• Swollen belly (fluid-filled)

• Difficulty breathing (if fluid is in the chest)

• Lethargy

• Fever that doesn’t respond to antibiotics

Dry (Non-Effusive) Form

• Weight loss

• Persistent fever

• Neurological signs (wobbliness, seizures)

• Eye inflammation or vision changes

• Organ involvement (kidneys, liver)

Both forms can overlap, and symptoms may progress quickly.

Diagnosis

Diagnosing FIP can be challenging, as there is no single definitive test. Veterinarians typically use a combination of:

• Clinical signs and history

• Bloodwork abnormalities

• Imaging (X-rays or ultrasound)

• Fluid analysis (if present)

Diagnosis is often based on ruling out other conditions and identifying patterns consistent with FIP.

Treatment & Management

FIP is now treatable, thanks to antiviral medications (such as GS-441524 and similar drugs):

• Treatment typically lasts around 12 weeks

• Many cats respond very well, especially when treatment starts early

• Regular monitoring is required during treatment

Supportive care may include:

• Fluids

• Nutritional support

• Medications for comfort and symptom management

Early detection and prompt treatment are key to success.

Prevention

While there is no guaranteed way to prevent FIP, you can reduce risk by:

• Maintaining clean litter boxes (frequent scooping and sanitation)

• Reducing overcrowding in multi-cat environments

• Minimizing stress

• Practicing good hygiene when introducing new cats

A vaccine exists but is not widely recommended due to limited effectiveness.

Human Health Concerns

FIP cannot be transmitted to humans or other non-feline species. It is specific to cats.

Living with a Cat Diagnosed with FIP

A diagnosis of FIP is no longer a hopeless situation. Many cats go on to live happy, healthy lives after treatment. With proper veterinary care, monitoring, and a supportive environment, recovery is possible.

FIP can be overwhelming, but there is real hope. If you suspect FIP or have a diagnosed cat, working closely with a knowledgeable veterinarian can make all the difference.