In the more severely affected cases, the cause for NT-proBNP elevation was probably the cardiac wall stress itself, as described for cardiomyopathy in cats [4, 7, 11, 16], primary heart disease in dogs (e.g., DCM and valve disease) [25, 26] and pulmonary hypertension or embolism in dogs [27, 28]. Here, NPPB is linked to pulmonary arterial hypertension.