Abstract
A post-mortem examination of an 8 years old German Shepherd dog was performed in order to find out the death cause. The macroscopically examination revealed a large amount of blood in the abdominal (hemoperitoneum) and pericardial cavity (hemopericardium) and also the rupture of the right atrium. The spleen was sampled for histopathological examination. Hematoxylin-eosin–methylene blue staining was performed in order to prepare the samples for microscopical examination. Based on the specific histopathological changes and taking into account all the pathological data, the diagnosis was hemangiosarcoma. Key words: hemangiosarcoma, German Shepherd dog, hematoxylin-eosin–methylene blue staining