BackgroundIn dogs with chronic valvular heart disease (CVHD), early recognition of pulmonary edema (PE) is of paramount importance. Recent studies in dogs showed that lung ultrasound examination (LUS) is a useful technique to diagnose cardiogenic PE.ObjectivesTo describe LUS features in dogs with different stages of CVHD, and to determine its diagnostic accuracy in detecting PE using thoracic radiography as the reference standard.AnimalsSixty‐three dogs with CVHD.MethodsProspective, multicenter, cross‐sectional study. Each dog underwent physical examination, echocardiography, thoracic radiography, and LUS. The LUS findings were classified as absent, rare, numerous, or confluent B‐lines. Sensitivity, specificity, and positive and negative predictive values of LUS B‐lines to identify PE were calculated using thoracic radiography as the reference standard.ResultsDogs in stage B1 had absent or rare B‐lines in 14 of 15 cases (93.3%). Dogs in stage B2 had absent or rare B‐lines in 16 of 18 cases (88.9%). All dogs in stage C, without radiographic signs of PE, had absent or rare B‐lines. Dogs in stage C, with radiographic signs of PE, had numerous or confluent B‐lines in 18 of 20 cases (90%). Lung ultrasound examination detected PE with a sensitivity of 90%, specificity of 93%, and with positive and negative predictive values of 85.7 and 95.2%, respectively.Conclusions and Clinical ImportanceLung ultrasound examination showed good diagnostic accuracy to identify cardiogenic PE and might be helpful in staging dogs with CVHD. Lung ultrasound examination should be considered as a new, noninvasive diagnostic tool for clinicians managing CVHD in dogs.