The use of the ELISA to measure circulating NP concentrations in cats will provide many opportunities to evaluate the use of these peptides for diagnostic, prognostic, and therapeutic purposes in the management of feline cardiovascular, respiratory, and renal disease. Early studies have shown great potential and some conflict with regard to their use as diagnostic aids. The goal now is to refine the interpretation of NP concentrations through further scientific studies and clinical practice to determine their full potential as an important biomarker in the assessment and management of common feline diseases.