Callie Kenya, a five year old spayed female Dwarf Rabbit, presented to Cornell University Exotics Service on September 19, 2008 for increased respiratory noise and labored breathing. Callie had also been exhibiting abnormal stretching behavior of her neck and head, as well as increased yawning and sneezing. On physical exam, there were increased bronchovesicular sounds bilaterally as well as increased expiratory effort during respiration. Her chest was non-compliant on palpation. Radiographs identified a mass effect in the cranioventral thorax. Additional diagnostics lead to a presumptive diagnosis of thymoma. Radiation therapy was the initial treatment implicated. After recurrence of the thymoma nine months after the last radiation treatment, the mass was surgically excised at a large out of state referral hospital. Histopathology later confirmed the initial diagnosis of thymoma.