Metastatic renal carcinoma in a horse presented for lameness examination and suspected pneumonia

Equine renal cell carcinoma (RCC) is a rare and poorly understood condition, making the diagnosis challenging. We present a case of a 16‐year‐old Warmblood gelding referred for lameness and suspected pneumonia. The horse exhibited diverse non‐specific symptoms, including pyrexia, coughing, weight loss and lameness. Diagnostic imaging revealed an osseous neoplastic lesion and lung metastasis. Postmortem confirmed metastatic renal carcinoma. This case underscores the difficulty of RCC diagnosis due to non‐specific clinical signs, necessitating a comprehensive approach involving clinical, imaging and histopathological findings. RCC offers limited treatment options as it is typically diagnosed at advanced stages, leading to a poor prognosis and euthanasia. Increased awareness and research are crucial for early detection and better understanding of this rare equine disease.