Bilateral Uveitis in a Horse With a Renal Carcinoma.

Equine uveitis is a common eye disease that affect horses from different breeds, ages, and genders. Uveitis has been described as inflammation of the uvea secondary immunomediated processes or eye trauma. Renal cell carcinoma (RCC) is the most common tumor that can affect the equine kidneys. The present case describe a horse that was referred to the Veterinary Teaching Hospital of the University of Extremadura with bilateral uveitis. The horse was treated for the primary complain but the horse collapse and die during hospitalization. At necropsy, a tumoral mass in kidney with extensive in other locations as liver, lung, and lymphonodes was described. Within peritoneal cavity a pedunculated mass has been observed next to severe hemoperitoneum. Histologically, primary neoplasia and its metastasis was composed by a proliferation of epithelial cells, which were organized in a tubulopapillary pattern, similarly in the ciliary body this pattern was also observed. The diagnosis of renal carcinoma with metastasis in both uveal structures was performed. Immunomarker with CD10, AE1-AE3, and vimentin evidenced the same origin of primary neoplasia. Uveal metastasis should be included as differential diagnoses in aged horses with uveitis that not response with the medical treatment.