Primary Cardiac Hemangiosarcomas in Dogs

SUMMARY Hemangiosarcoma of the heart was diagnosed and studied retrospectively in 31 dogs at the Angell Memorial Animal Hospital. The disease was found most frequently in old dogs, especially German Shepherd Dogs. The clinical signs were characterized by weakness or prostration, weight loss, pallor, and respiratory difficulties. Signs of cardiac disease and brain disorders were frequently encountered. Frequently tumors or hemorrhage into body cavities were detected by palpation, paracentesis, radiography, or exploratory surgery. Hematologic findings disclosed anemia, leukocytosis due to neutrophilia, and left shift. Nucleated erythrocytes were frequently abundant (a helpful diagnostic feature), probably as a result of active hematopoiesis and hypoxemia. The cardiac tumors were consistently located in the right atrium (except in 1 dog); often they were restricted to an area near the coronary groove and entrance of the auricle. Thrombi covered endocardial extensions of some tumors, and in some dogs rupture of the tumorous right atrium led to hemopericardium or tamponade with sudden death. Metastases were widespread and frequently found in the lungs, liver, spleen, and kidneys. Metastasis, infarcts, or hemorrhages were not unusual findings in the brain.