Abdominal Enlargement

💧 Abdominal Enlargement in Cats with FIP

Overview

Abdominal enlargement is a hallmark clinical sign of the wet form of feline infectious peritonitis (FIP). It occurs when inflammatory fluid accumulates within the abdominal cavity (ascites), causing visible distension of the abdomen.

In some cases, fluid may also accumulate in the chest cavity (pleural effusion), which can impair breathing and reduce exercise tolerance.

Common Signs

Cats with abdominal enlargement may exhibit:

• 📈 Progressive abdominal swelling or distension

• ⚖️ Rapid increase in abdominal girth despite overall weight loss

• 😮‍💨 Difficulty breathing or increased respiratory effort

• 😿 Reduced activity and lethargy

• 🍽️ Decreased appetite

• 🪑 Reluctance to move, jump, or lie comfortably

• 💙 Cool extremities in advanced cases due to poor circulation

Abdominal swelling may appear suddenly or gradually and can worsen rapidly.

Why Does FIP Cause Abdominal Fluid Accumulation?

Wet FIP causes inflammation of blood vessels (vasculitis), leading to increased vascular permeability. Protein-rich fluid leaks into body cavities, especially the abdomen and chest.

This fluid accumulation contributes to:

• Increased abdominal pressure

• Reduced lung expansion

• Impaired organ function

• Reduced comfort and mobility

When Should You Seek Veterinary Care?

Urgent veterinary evaluation is recommended if a cat shows:

• Sudden or progressive abdominal swelling

• Labored or rapid breathing

• Loss of appetite or weakness

• Concurrent fever, weight loss, or neurologic signs

• Signs of discomfort or collapse

Fluid accumulation can progress quickly and may become life-threatening without medical supervision.

Diagnostic Evaluation

Veterinarians may assess abdominal enlargement using:

• Physical examination and abdominal palpation

• Ultrasound imaging

• Radiography (X-ray)

• Abdominocentesis (fluid sampling)

• Fluid analysis (protein content, cytology, Rivalta test)

• Blood testing and inflammatory markers

Results are interpreted together with clinical history and imaging findings.

Authoritative References

This content is based on guidance from:

• Cornell University College of Veterinary Medicine

• Merck Veterinary Manual

• VCA Animal Hospitals

• International Society of Feline Medicine (ISFM)

• American Association of Feline Practitioners (AAFP)

⚠ Medical Disclaimer

This content is provided for educational purposes only and does not replace professional veterinary diagnosis or treatment. Always consult a licensed veterinarian for medical decisions.