Clinical utility of point-of-care lactate measurement for assessing management status and prognosis in dogs with myxomatous mitral valve disease.

Introduction: Myxomatous mitral valve disease (MMVD) is a chronic cardiac condition that can have serious hemodynamic consequences and therefore requires lifelong monitoring. However, although echocardiography remains the gold standard for diagnosis and staging, its repetition at short intervals to assess therapeutic response can be limited by cost, logistics, and patient tolerance. In this context, biomarkers such as lactate could serve as a complementary tool to reflect clinical status and prognosis. This study aimed to evaluate the clinical utility of point-of-care (POC) whole blood lactate measurement in dogs with MMVD, with a particular focus on its ability to reflect clinical status within American College of Veterinary Internal Medicine (ACVIM) stages B2 and C. Methods: This retrospective observational study included 33 client-owned dogs with MMVD examined between June 2025 and November 2025. The population had a mean age of 13.6 years and mean body weight of 4.3 kg. Dogs were classified according to ACVIM stage and clinical status at presentation into three groups: Stage B2 ( Results: Whole blood lactate concentrations differed significantly among the three groups ( Discussion: POC whole blood lactate measurement can serve as a valuable adjunctive screening tool for assessing clinical management status and acute hemodynamic condition in dogs with MMVD. However, lactate values approximating the identified cut-off of 3.0 mmol/L should not be interpreted as a binary decision threshold. Instead, values in this range indicate a zone of increased clinical uncertainty, warranting closer monitoring and hemodynamic reassessment in conjunction with standard clinical evaluation.