Pleural Effusion in Cats

Pleural effusion is the abnormal accumulation of fluid within the chest cavity, which is lined by a membrane -- the pleural lining. This occurs in cats either because too little fluid is being absorbed in the pleural cavity, or because too much fluid is being produced in the pleural cavity. Alterations in the cat's blood pressure and protein content in the blood, or the penetrability of blood vessels and lymphatic function, may contribute to fluid accumulation.

The condition or disease described in this medical article can affect both dogs and cats. If you would like to learn more about how this disease affects dogs please visit this page in the PetMD health library.

Symptoms and Types

• Coughing
• Difficulty breathing
• Increased rate of breathing
• Cat places itself in unusual positions to ease breathing
• Open-mouth breathing
• Bluish to purplish color of skin
• Exercise intolerance
• Lack of energy
• Lack of appetite

Causes

• High hydrostatic (fluid) pressure
• Low Oncotic Pressure: inability of blood plasma proteins to pull water into the circulatory system, resulting in excess fluid build-up (edema)
• Vascular or lymphatic abnormality: disorders of the vessels and/or ducts that convey fluids
• Chest filled with lymph fluid mixed with lipids (fat particles)
• Lymphangiectasia (dilation of the lymph vessels)
• Diaphragmatic hernia: passage of a loop of intestine through an abnormal hole in the diaphragm muscle (which separates the chest cavity from the abdominal cavity)
• Blockage of the vena cava – the major vein from the lower part of the body that feeds into the heart
• Congestive heart failure (CHF)
• Cancer in the chest cavity
• Blood in the chest cavity
• Trauma to the chest
• Lung lobe torsion (twisting)
• Blood clot of the lungs
• Infection: bacterial, viral, or fungal
• Heartworms
• Hypoalbuminemia: abnormally low levels of blood protein albumin
• Protein-losing enteropathy (intestinal disease)
• Protein-losing nephropathy (kidney disease)
• Liver disease
• Inflammation of the pancreas
• Overhydration
• Bleeding disorder