Wet FIP in Cats: Symptoms, Diagnosis & Treatment

Feline Infectious Peritonitis (FIP) is one of the most devastating diseases affecting cats, particularly young ones. Among its two forms—wet (effusive) and dry (non-effusive)—wet FIP is the more acute and recognizable version. It often progresses rapidly, but with timely diagnosis and modern antiviral treatments, survival is now possible.

At CureFIP.com, our mission is to support cat owners and veterinarians with expert information and proven treatment solutions. In this guide, we’ll explore everything you need to know about wet FIP: what it is, why it happens, how to spot the signs, and what treatment options are available today.

What Is Wet FIP?

Wet FIP, also known as effusive FIP, is a form of feline infectious peritonitis characterized by the accumulation of fluid in body cavities—most commonly the abdomen or chest.

It results from an inappropriate immune response to a mutated form of feline coronavirus (FCoV). This immune reaction causes widespread inflammation of blood vessels (vasculitis), leading to leakage of fluid.

Quick Facts:

Cause: Mutated feline coronavirus (FIPV)

Common in: Kittens and cats under 2 years old

Primary symptom: Fluid buildup in the abdomen or chest

Progression: Rapid, often fatal without treatment

Symptoms of Wet FIP

Wet FIP is often easier to recognize due to fluid accumulation, which causes noticeable changes in the cat’s body and behaviour.

Common Clinical Signs

Swollen or distended abdomen

• Caused by fluid buildup (ascites) in the abdominal cavity.
  

Difficulty breathing

• Indicates pleural effusion (fluid in the chest cavity).
  

A fever that doesn’t respond to antibiotics

• Persistent, fluctuating fever is a hallmark sign of FIP.
  

Lethargy and weakness

• Cats may sleep more, move less, and seem depressed.

Loss of appetite and weight loss

• Rapid deterioration of body condition.
  

Pale gums or jaundice

• May indicate liver involvement or anemia.
  

Diarrhoea or vomiting

• In some cases, due to gastrointestinal inflammation.
  

The symptoms progress quickly. In untreated cases, wet FIP can become fatal in days to weeks.

How Is Wet FIP Diagnosed?

There is no single test that confirms FIP 100%, but a combination of clinical signs, imaging, lab tests, and fluid analysis can strongly support the diagnosis.

1. Physical Examination

• Palpation of a fluid-filled abdomen

• Signs of fever and poor condition
  

2. Ultrasound or X-ray

• Detects fluid accumulation in the chest or abdomen
  

3. Analysis of Effusion Fluid

Wet FIP fluid is typically:

• Straw-coloured

• Sticky and viscous

• High in protein (>3.5 g/dL)

• Low in cells
  

4. Blood Tests

• Elevated globulins

• Decreased albumin/globulin (A/G) ratio (<0.4 is strongly suggestive)

• Mild anemia

• Increased bilirubin (especially if jaundice is present)
  

5. PCR Test (optional)

• Detects FCoV RNA in body fluid or tissue

• False negatives and positives are possible, so results must be interpreted in context
  

Is Wet FIP Contagious?

No, wet FIP itself is not contagious.

What is contagious is the feline coronavirus (FCoV), which can spread through:

• Shared litter boxes

• Grooming

• Contaminated surfaces or bowls
  

However, only a small portion of cats with FCoV will develop FIP, and once it mutates into the FIPV form, it cannot spread between cats.

Treatment Options for Wet FIP

Until recently, FIP was considered universally fatal, but scientific breakthroughs have changed that outlook.

GS-441524: The Game-Changer

GS-441524 is an antiviral drug that inhibits FIP virus replication and is the foundation of successful FIP treatment today.

Key Treatment Details:

• Form: Injectable or oral

• Duration: 84-day treatment protocol

• Dosage: Based on weight and FIP type (wet FIP usually requires moderate dosing)

• Monitoring: Regular checkups, blood tests, and weight tracking
  

Success Rate:

• 85–90% of cats recover when treated early and consistently

At CureFIP.com, we provide:

• GS-441524 treatment support

• Monitoring tools (like treatment apps)

• Free expert consultation

• 24/7 guidance through every stage of recovery
  

Prognosis and Recovery

Without Treatment:

Wet FIP progresses rapidly and is usually fatal within 1–4 weeks

With Treatment:

• Most cats begin improving within 3–10 days

• Full recovery is possible within 3–6 months post-treatment

• Lifespan after recovery is normal in most cases
  

The earlier the diagnosis and the sooner the treatment begins, the better the outcome.

Preventing Wet FIP

Although FIP isn’t directly preventable, reducing FCoV exposure can help.

Prevention Tips:

• Minimise crowding in shelters and catteries

• Maintain strict litter box hygiene

• Avoid early weaning and high-stress environments for kittens

• Isolate FIP-diagnosed cats (not due to contagion, but for comfort and monitoring)

• Avoid breeding cats with a FIP family history

Final Thoughts: Wet FIP Can Be Treated

Wet FIP is no longer a death sentence. With the right information, early intervention, and access to GS-441524-based treatment, many cats are now recovering and living full lives.

At CureFIP.com, we are here to help you every step of the way—from symptom recognition to full recovery.

If you suspect your cat has wet FIP, don’t wait. Contact us for a consultation and start the path to healing.