Mitral annular disjunction (MAD) has been defined as a structural abnormality with separation between the posterior leaflet of the mitral valve and the left atrial wall. It is commonly associated with myxomatous mitral valve disease (MMVD), mitral valve prolapse (MVP), ventricular arrhythmias, and sudden cardiac death in humans, but has not been described in veterinary medicine despite the high prevalence of MMVD in the canine population. The echocardiographic findings in a Chihuahua with MAD, MMVD, and MVP are described. Diagnostic methods and criteria are reviewed and adapted.

中文翻译：

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狗的二尖瓣环分离和粘液性二尖瓣疾病

二尖瓣环分离（MAD）被定义为二尖瓣后叶与左心房壁分离的结构异常。它通常与人类的粘液性二尖瓣疾病（MMVD）、二尖瓣脱垂（MVP）、室性心律失常和心源性猝死有关，但尽管MMVD在犬类中患病率很高，但在兽医学中尚未得到描述。描述了患有 MAD、MMVD 和 MVP 的吉娃娃犬的超声心动图检查结果。诊断方法和标准经过审查和调整。