Abstract
A 10-year-old female toy poodle dog was diagnosed as angiosarcoma of the right atrium. The ultrasonographic examination detected the tumor mass of 2 cm in the basal part of the right atrium, causing cardiac tamponade.
The autopsy revealed an angiosarcoma which may be resulted from repeated hemorrhage. There was no metastasis in other organs. Based on these findings, the lesion was diagnosed as the primary angiosarcoma.