Vol. 10, Issue 9, Part A (2025)

Hemangiosarcoma (HSA) is a malignant neoplasm originating from vascular endothelial cells and is known for its aggressive behavior, high metastatic potential, and hemorrhagic characteristics. Though well-documented in dogs, its incidence in small ruminants like sheep is exceptionally rare. This case report describes a primary pulmonary hemangiosarcoma in a 5-year-old breeding ram that succumbed to sudden death following a brief clinical history of respiratory distress. Postmortem examination revealed non-collapsing, hemorrhagic lungs with thoracic effusion and a cystic lesion. Impression smear revealed spindled shaped anisocytic neoplastic cells with pleomorphic round to oval nucleus with prominent nucleoli. Histopathological evaluation confirmed neoplastic endothelial proliferation forming irregular vascular channels with hemorrhage. Based on gross, cytology and histopathological examination present case diagnosed as pulmonary hemangiosarcoma.