Ocular histiocytic sarcomas (as a presenting part of disseminated histiocytic sarcoma) are not commonly diagnosed. A 10-year-old female intact Rottweiler presented to the School of Veterinary Medicine, Trinidad with buphthalmia and pain in the left eye. The cornea of the left eye appeared diffusely opaque with a conjunctival mucopurulent ocular discharge. A thorough ophthalmic assessment identified an intraocular proliferative tumor to which a unilateral enucleation was performed, however the animal died soon after. Post mortem examination and light microscopy revealed that the intraocular lesion with visceral macro-metastases was in fact a histiocytic sarcoma. Further to this, immune-phenotyping was performed to confirm the diagnosis of disseminated histiocytic sarcoma. This is the first time such a tumor has been diagnosed in Trinidad and Tobago.