Abstract
A seven‐year‐old, 550‐kg, Bavarian warmblood gelding was referred to the Ophthalmology Service of the Veterinary University Vienna, due to a mass on the bulbar aspect of the nictitating membrane of the left eye. Thorough ophthalmic examination of the left eye revealed a red‐pink mass, about 1 cm in diameter and 4 mm thickness, on the bulbar aspect of the nictitating membrane. Histopathological and immunohistological examination of the excised mass identified a T‐cell‐rich large B‐cell lymphoma. Follow‐up examination revealed no recurrence of the mass 18 months after initial presentation. To the authors' knowledge this is the first report of a histopathologically confirmed T‐cell‐rich large B‐cell lymphoma of the ocular adnexa in the horse, with no recurrence or metastasis 18 months after initial presentation.