Dilated cardiomyopathy (DCM) is a frequent cause of cardiac disability, congestive heart failure (CHF) and arrhythmic death in dogs. The etiology of DCM is usually idiopathic/genetic, but some causes of a DCM phenotype are reversible. The disease is classified into preclinical (occult) and clinical (overt) stages; the latter stems from heart failure with reduced ejection fraction. DCM is further characterized by clinical, electrocardiographic, circulating biomarker, and imaging abnormalities. The diagnosis of clinical DCM with CHF is straightforward; however, identification of the preclinical stage can be challenging. Echocardiography is central to the diagnosis of both stages, and characterized by left ventricular (LV) systolic dysfunction with progressive chamber dilation, and variable enlargements of the left atrium and right-sided chambers. Left ventricular dilation is defined by increased LV end-diastolic volumes, areas, and internal dimensions normalized to body size or indexed to the aorta. Systolic dysfunction is characterized by decreased LV ejection fraction, increased end-systolic volume, and reduced shortening across minor and longitudinal LV axes. Dyssynchrony can confound the interpretation of linear indices of systolic function. A comprehensive echocardiogram in DCM includes two-dimensional (2D) and M-mode studies, spectral and tissue Doppler imaging, and potentially three-dimensional echocardiography and myocardial strain imaging. Echocardiographic findings should be interpreted within the context of identifiable risks and comorbidities, physical diagnosis, complementary diagnostic testing, and limitations of current reference intervals. Ambiguous examinations should be repeated. Specific echocardiographic criteria for the diagnosis of DCM are proposed to encourage discussion and additional outcome and breed-specific echocardiographic studies of canine DCM.

扩张型心肌病 (DCM) 是导致犬心脏残疾、充血性心力衰竭 (CHF) 和心律失常死亡的常见原因。DCM 的病因通常是特发性/遗传，但 DCM 表型的某些原因是可逆的。该疾病分为临床前（隐匿）和临床（明显）阶段；后者源于射血分数降低的心力衰竭。DCM 的特征还在于临床、心电图、循环生物标志物和影像学异常。临床 DCM 合并 CHF 的诊断很简单。然而，临床前阶段的识别可能具有挑战性。超声心动图是这两个阶段诊断的核心，其特征是左心室 (LV) 收缩功能障碍伴心室进行性扩张，以及左心房和右侧心室的可变扩大。左心室扩张定义为增加的 LV 舒张末期容积、面积和内部尺寸，标准化为身体大小或与主动脉挂钩。收缩功能障碍的特点是 LV 射血分数降低，收缩末期容积增加，以及 LV 短轴和纵轴的缩短减少。不同步会混淆对收缩功能线性指数的解释。DCM 中的综合超声心动图包括二维 (2D) 和 M 模式研究、频谱和组织多普勒成像，以及可能的三维超声心动图和心肌应变成像。超声心动图检查结果应在可识别的风险和合并症、物理诊断、补充诊断测试和当前参考区间的限制的背景下进行解释。应重复模棱两可的检查。提出了用于诊断 DCM 的特定超声心动图标准，以鼓励对犬 DCM 进行讨论和额外的结果和品种特异性超声心动图研究。