Axial osteosarcoma is a malignant mesenchymal tumor that mainly affects middle-aged to elderly animals of medium and large breeds. This article describes the first case of telangiectatic osteosarcoma in the state of Pernambuco. The animal initially presented a tumor in the left chest wall as the only symptom. The diagnosis was confirmed after surgical excision of the tumor and sending it for histopathology. The patient was treated with a combination of surgery and chemotherapy based on carboplatin and doxorubicin. The prognosis for the telangiectatic subtype is more unfavorable when compared to other subtypes. Patient survival time was 6 months from the onset of tumor growth.
