Measurement of plasma concentrations of natriuretic peptides have been suggested to be of diagnostic and prognostic value in canine cardiac disease. In several previous canine studies, however, a considerable overlap between investigated groups has been identified. A reliable natriuretic peptide test for use in clinical practice requires establishment of reference values for natriuretic peptides in healthy dogs and cut-off values for subclinical disease as well as for clinical signs of congestive heart failure. Numerous physiological, pathological and pharmacological factors, aside heart function, may influence concentration of natriuretic peptides. A potential effect of dog breed on natriuretic peptide concentration has been suggested but has, to our knowledge, not previously been specifically studied.