Assessment of circulating N-terminal pro B-type natriuretic peptide concentration to differentiate between cardiac from noncardiac causes of pleural effusion in cats


  • Dr. Schneider is a consultant for IDEXX Laboratories.

  • The authors declare no other conflict of interest.

Address correspondence and reprint requests to Dr. Esther Hassdenteufel, Small Animal Clinic, Frankfurterstr. 126, 35392 Giessen, Germany. Email:



To determine the diagnostic ability of blood N-terminal pro B-type natriuretic peptide (NT-proBNP) measurement to differentiate between congestive heart failure (CHF) and noncardiogenic causes for moderate to severe pleural effusion in cats.


Prospective observational study.


University teaching hospital.


Twenty-one cats with moderate to severe pleural effusion.


Venous blood sampling for NT-proBNP measurement.

Measurement and Results

According to the results of echocardiographic examination, cats were classified in a group with CHF (n = 11) or noncongestive heart failure (N-CHF, n = 10). NT-proBNP was measured via a feline-specific test in EDTA plasma with protease inhibitor. NT-proBNP was significantly (P < 0.0001) higher in the CHF group ( median 982 pmol/L, 355–1,286 pmol/L) than in the N-CHF group (median 69 pmol/L, 26 – 160 pmol/L) and discriminated exactly (area under the curve = 1.0, 95% confidence interval 1.0–1.0) between both groups. Optimum cut-off value considering all samples was 258 pmol/L.


In this small population of cats with pleural effusion, NT-proBNP was able to differentiate between cats with cardiogenic and noncardiogenic causes of effusion. With the currently recommended method of measurement (ie, EDTA plasma with protease inhibitor), a cut-off value of 258 pmol/L discriminates effectively between cats with and without CHF.