The fluid can give an indication of '''prognosis'''; in the cat prognosis is generally poor for all diagnoses except [[Pyothorax|pyothorax]] (an exudate with degenerate [[neutrophils]] and intracellular bacteria). Therefore it is often useful to perform in-house cytology to give a preliminary diagnosis, which allows the owners to make an informed decision before proceeding with further treatment. Differential diagnosis in the cat include [[Heart Failure|congestive heart failure]], [[Feline Infectious Peritonitis|FIP]], [[Pyothorax|pyothorax]], [[Neoplasia - Pathology|neoplasia]], [[Haemothorax|haemothorax]] and [[Chylothorax|chylothorax]]. ''It should be noted that any pleural effusion may produce bizarre [[mesothelial cells]] which could be mistaken for neoplastic cells.'' | The fluid can give an indication of '''prognosis'''; in the cat prognosis is generally poor for all diagnoses except [[Pyothorax|pyothorax]] (an exudate with degenerate [[neutrophils]] and intracellular bacteria). Therefore it is often useful to perform in-house cytology to give a preliminary diagnosis, which allows the owners to make an informed decision before proceeding with further treatment. Differential diagnosis in the cat include [[Heart Failure|congestive heart failure]], [[Feline Infectious Peritonitis|FIP]], [[Pyothorax|pyothorax]], [[Neoplasia - Pathology|neoplasia]], [[Haemothorax|haemothorax]] and [[Chylothorax|chylothorax]]. ''It should be noted that any pleural effusion may produce bizarre [[mesothelial cells]] which could be mistaken for neoplastic cells.'' |