Clinical Utility of Point-of-Care Lactate Measurement for Assessing Management Status and Prognosis in Dogs with Myxomatous Mitral Valve Disease

Wangyu Choi¹Ji-young Ha²Eon-seung Jeong³Young-Min Yun^1*

• ¹Jeju National University, Jeju-si, Republic of Korea
• ²Jamsil Best animal Medical center, Seoul, Republic of Korea
• ³SEEU Animal Medical Center, Seoul, Republic of Korea

Myxomatous mitral valve disease (MMVD) is a chronic cardiac condition with potentially serious hemodynamic consequences that requires lifelong monitoring. Although echocardiography remains the gold standard for diagnosis, repeated short-interval reassessments to evaluate therapeutic response may be limited by cost, logistics, and patient tolerance. In this context, biomarkers such as lactate can provide complementary information regarding 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, focusing on its ability to reflect clinical status within American College of Veterinary Internal Medicine (ACVIM) stages B2 and C. This retrospective study included 33 client-owned dogs with MMVD classified as Stage B2 (n = 13), Stage C with controlled congestive heart failure (CHF) (n = 13), or Stage C with acute decompensated CHF (n = 7). Whole blood lactate was measured by POC capillary sampling from the paw pad after approximately 5 minutes of acclimatization. Whole blood lactate concentrations differed significantly among the three groups (P = 0.002). Dogs with Stage C and acute decompensated CHF exhibited a markedly higher mean lactate concentration (5.61 ± 1.98 mmol/L) compared with dogs in Stage B2 (2.17 ± 0.95 mmol/L) and those with Stage C and controlled CHF (2.50 ± 1.04 mmol/L) (P = 0.002). No significant difference was observed between the Stage B2 and Stage C with controlled CHF groups (P = 0.456). Receiver operating characteristic analysis yielded an area under the curve of 0.94 (95% CI: 0.85–1.00, P < 0.001). At a cut-off value of 3.0 mmol/L, lactate measurement demonstrated a sensitivity of 100%, specificity of 72%, and a negative predictive value of 100%. 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.