What is the expected appearance of a thoracic effusion due to FIP?

The expected appearance of a thoracic effusion due to feline infectious peritonitis (FIP) is light gold with high protein levels. This characteristic appearance is a result of the immune-mediated inflammatory response associated with the disease. FIP is known to produce a type of effusion that is rich in protein and often has a yellowish tint, signaling the presence of inflammatory cells and other proteins in the fluid.

This effusion typically has a specific gravity greater than 1.020 and a total protein concentration that is often above 3 g/dL. The high protein and modified transudate characteristics distinguish it from other types of effusions you might encounter in different conditions.

The light gold color and high protein content are critical diagnostic indicators that veterinarians use when evaluating thoracic effusions in suspected FIP cases. Careful analysis of the fluid is vital, as it aids in differentiating FIP from other causes of effusion, which may have different attributes and underlying causes.