A 9 year old female spayed, toy poodle presented to Cornell Veterinary Hospital for Animals’ Neurology Service for surgical treatment of a third ventricle brain tumor that was diagnosed on magnetic resonance imaging (MRI) by a referring veterinary neurologist. Historically, the patient was a healthy dog at home with no known systemic illness. One month prior to presentation, she developed cervical and thoracic spine pain. A week later, she became non-ambulatory, blind, developed a right head tilt, right head turn, and had several episodes of rigidity and neck extension. MRI revealed a large tumor within the lateral and third ventricles with secondary mass effect. The patient was then referred for surgical intervention. On presentation to Cornell Neurology Service, the patient’s neurologic exam was consistent with a left-sided forebrain lesion. She was scheduled for surgery the following day, however, the patient became unstable later that afternoon showing signs of a Cushing reflex. She was minimally responsive to several boluses of mannitol and hypertonic saline and rushed into an emergency craniotomy. Intraoperatively, she experienced significant meningeal bleeding and was given a blood transfusion. A moderate amount of tumor was removed and samples were submitted for histopathology. Complete surgical excision was not possible due to the tumor location and the inability to differentiate tumor from healthy brain tissue. The patient recovered uneventfully from anesthesia without requiring mechanical ventilation. That evening, she became moderately hypertensive and was treated with a mannitol bolus to which she responded well. Two days postoperative she developed a cough and was prophylactically treated for aspiration pneumonia. Her cough subsided within 48 hours and she remained stable during her hospitalization over the next three days. Five days postoperative, the patient showed mild improvements on neurologic exam, including inconsistent menace in the left eye, normally pupillary light reflexes in both eyes, and increased right nasal sensation. She was deemed stable for discharge and was sent home on prednisone, pregabalin, amoxicillin and clavulanic acid , levetiracetam, and the recommendation for follow-up radiation therapy. One month postoperative, the patient was seen by Cornell Oncology Service 2 for a radiation therapy consult. She did poorly under general anesthesia and radiation therapy was no longer a safe treatment option. She remained comfortable at home, showing small improvements each day. Three months later, she was euthanized due to the development of refractory cluster seizures.