LAUSR

Abstract A 3-year-old male guinea pig (Cavia porcellus) presented to the UNAM Exotic Pet and Wildlife Teaching Hospital. Clinical signs included hyphema, buphthalmos, goniosynechiae, anterior uveitis, and hypopyon of the ventral iridocorneal angle of the right eye. The right globe was enucleated and submitted for histopathology and the histopathologic findings were consistent with osteosarcoma. Thoracic radiographs did not reveal evidence of other primary tumors or metastasis. Four months later, the patient had pleural friction rub sounds upon auscultation of the lung fields and prescapular lymphadenomegaly. Radiographic evaluation revealed a radiopaque mineral-dense structure in the right caudal pulmonary lobe, suggestive of osteosarcoma metastasis. The presumptive diagnosis was confirmed at necropsy. This is the first report of a primary intraocular osteosarcoma in a guinea pig.