Robinson W F, Huxtable C R, Pass D A
Vet Pathol. 1980 May;17(3):282-93. doi: 10.1177/030098588001700302.
Naturally occurring acute parvoviral myocarditis in puppies 3 to 8 weeks of age was characterised clinically by sudden death or death following a brief period of dyspnoea. Mortality within litters varied from 20% to 100%. The principal lesion was in the myocardium, which in most cases was mottled by pale patches and bands. Moderate to severe pulmonary oedema with marked peribronchial and perivascular oedema was present. In some cases, the wall of the gall bladder was oedematous. Microscopically the ventricular myocardium had myofibre loss, multifocal myofibre necrosis, a mononuclear cell infiltrate of variable intensity and reactive stromal elements. In every case there were Feulgen-positive, amphophilic, and reactive stromal elements. In every case there were Feulgen-positive, amphophilic, intranuclear inclusion bodies in myocardial nuclei. Ultrastructurally the inclusions were composed of dense granular material and particles resembling parvovirions. Pulmonary alveolar septae were thickened by fibroblasts. Peribronchial and perivascular lymphatics were distended with oedema fluid and occasionally erythrocytes. The pulmonary lesions were considered secondary to the myocardial dysfunction. Some of the puppies that survived the acute disease developed ventricular myocardial fibrosis and died in congestive heart failure.
3至8周龄幼犬自然发生的急性细小病毒心肌炎，临床特征为猝死或在短时间呼吸困难后死亡。同窝幼犬的死亡率在20%至100%之间。主要病变位于心肌，多数情况下心肌有苍白斑块和条纹形成的斑驳状。存在中度至重度肺水肿，并伴有明显的支气管周围和血管周围水肿。部分病例中，胆囊壁水肿。显微镜下，心室心肌出现肌纤维丢失、多灶性肌纤维坏死、强度不一的单核细胞浸润以及反应性间质成分。每例均可见Feulgen阳性、嗜双色性的核内包涵体以及反应性间质成分。心肌细胞核内均有Feulgen阳性、嗜双色性的核内包涵体。超微结构下，包涵体由致密颗粒物质和类似细小病毒颗粒的粒子组成。肺泡间隔因成纤维细胞而增厚。支气管周围和血管周围淋巴管因水肿液而扩张，偶尔还有红细胞。肺部病变被认为是心肌功能障碍的继发表现。一些急性疾病存活下来的幼犬出现心室心肌纤维化，并死于充血性心力衰竭。
