Primary rib haemangiosarcoma in two dogs

Abstract

Primary rib haemangiosarcoma is an uncommon neoplasm, with only 24 cases reported since 1974. We describe the clinical presentation, diagnostic findings, and outcomes of two dogs with this condition. One dog was younger than 4 years old. Clinical signs included a palpable thoracic mass, lethargy, hyporexia, dyspnoea, pale mucous membranes and haemorrhagic pleural effusion. Thoracic computed tomography revealed caudal rib masses in both dogs; one also had pulmonary metastasis and sternal lymphadenopathy. Histopathology confirmed haemangiosarcoma in both cases. One dog was euthanased at diagnosis, while the other underwent wide rib resection and received lomustine, but was euthanased 45 days later due to recurrent haemorrhagic pleural effusion. These cases highlight that rib haemangiosarcoma can occur in young dogs, often presenting with acute clinical decline. Computed tomography is valuable for detecting rib lesions and metastasis, and prognosis remains poor despite aggressive treatment.