Clinical Stabilization Following Nephrectomy in a Dog with High-Grade Renal Cell Carcinoma: A Case Report

Renal cell carcinoma (RCC) is the most common primary malignant renal neoplasm in dogs, although rarely encountered in practice and often diagnosed at advanced stages. We report the clinical presentation, diagnostic evaluation, surgical management, and histopathological findings of RCC in a dog. A 7-year-old castrated male domestic dog presented with acute weight loss, inappetence, and a poor body condition score of 2/5. Diagnostic workup included clinical examination, hematology, serum biochemistry, abdominal radiography, exploratory laparotomy, and subsequent histopathological assessment of the excised renal mass. Clinical examination revealed cachexia, and abdominal palpation identified a firm ventral abdominal mass. Serum biochemistry demonstrated mild azotemia with elevated creatinine (1.19 mg/dL) and normal urea (90 mg/dL), resulting in a decreased BUN/creatinine ratio (12). Total protein (8.5 g/dL) and globulin (5.6 g/dL) were markedly elevated, with albumin remaining within the reference range (2.8 g/dL), leading to a reduced albumin/globulin ratio of 0.5. Vector-borne disease testing was negative. Abdominal radiography revealed a well-defined soft tissue opacity occupying the mid-abdomen, measuring approximately 13.9 × 13.3 cm. Exploratory laparotomy identified a well-encapsulated left renal mass, which was excised via unilateral nephrectomy. Histopathological examination confirmed a tubular-to-solid renal epithelial neoplasm with multifocal necrosis, hemorrhage, and a high mitotic index (72 per 10 high-power field), consistent with Grade 4 RCC, indicating poor prognosis. This case highlights the importance of comprehensive diagnostic evaluation and timely surgical intervention in canine renal tumors. Despite a poor prognosis associated with a high histological grade, curative-intent nephrectomy achieved clinical stabilization and short-term improvement in quality of life.