A three year old, male neutered American Bulldog presented to Cornell University Hospital for Animals (CUHA) Oncology Service for a mass of the third eyelid gland of his right eye. Histopathology of a lumpectomy performed two weeks prior to presentation reported a poorly differentiated squamous cell carcinoma. Staging workup, including complete blood count (CBC), chemistry panel, thoracic radiographs, and regional lymph node aspiration revealed no evidence of metastasis. Exenteration of the right eye was performed by CUHA Ophthalmology Service one week later for the best long-term prognosis in this patient. Histopathology of the exenterated eye and adnexa was performed by the Comparative Ocular Pathology Laboratory of Wisconsin, and favored a diagnosis of solid carcinoma of the third eyelid. There are few documentations of the biological behavior of third eyelid carcinomas. Non-steroidal anti-inflammatory therapy with regular monitoring of CBC, chemistry panel and orbital ultrasound of the right eye socket was initiated as long-term management.