Bilateral renal sarcoma in a bitch

Renal neoplasias are rare in dogs. When these occur, they usually affect middle-aged dogs from medium to large breeds, and most of them with malignant behavior. Only 7-11% of these tumors are of mesenchymal origin. Renal mesenchymal metastases appear most frequently in the lungs and abdominal organs. Clinical signs are non-specific, such as weight loss, inappetence and hematuria. This article describes a case of renal stromal sarcoma in a 7-year-old Rottweiler bitch. The main symptoms were fatigue and prostration. Exams showed anemia and neoplastic lesions in both kidneys, liver and jejunum. Ultrasound-guided fine-needle aspiration was inconclusive. Final diagnosis was achieved port-mortem, through tissue biopsy and immunohistochemistry.