To establish reference intervals for echocardiographic measures of longitudinal left ventricular function in adult English Springer spaniel (ESS) dogs.This study involved 42 healthy adult ESS.Animals were prospectively recruited from a general practice population in the United Kingdom. Dogs were examined twice, at least 12 months apart, to exclude dogs with progressive cardiac disease. Mitral annular plane systolic excursion, tissue Doppler imaging mitral annular velocities and two-dimensional speckle-tracking echocardiographic left ventricular longitudinal strain and strain rate were measured. Intraoperator and intraobserver variability were examined and reference intervals were calculated. The potential effects of body weight, age and heart rate on these variables were examined.Intraoperator and intraobserver variability was <10% for all parameters except tissue Doppler imaging E′ (the peak velocity of early diastolic mitral annular motion as determined by pulsed wave Doppler) and two-dimensional speckle-tracking echocardiographic variables, which were all <20%. Thirty-nine dogs were used to create reference intervals. Significant (but mostly weak) effects of age, heart rate and body weight on were detected. Reference intervals were similar to previously published values in different breeds.Breed specific reference intervals for measures of longitudinal left ventricular function in the ESS are presented.