Although cardiac diseases are common in cats and dogs, it can be challenging to diagnose, monitor, and predict outcomes in these cases. As a result, many different methods are often employed to assess the cardiac status of a patient, including auscultation, radiography, blood pressure, and echocardiography. It was 10 years ago that a new cardiac biomarker, NT-proBNP (N-terminal pro B-type natriuretic peptide), was introduced to veterinary medicine. As with any new tool, it has taken time to understand the benefits and limitations of this test for assessing cardiac health.