A 9-year-old, male, neutered Golden Retriever dog was presented to the Western College of Veterinary Medicine Veterinary Medical Center (Saskatoon, Saskatchewan, Canada) because of several grand mal seizures that had occurred over the preceding 3 weeks. There was no history of any previous neurologic abnormalities, but the dog had recently finished a course of cephalexin and prednisone prescribed for recurrent skin disease by the referring veterinarian. Other than evidence of osteoarthritis, no abnormalities were detected on physical examination; neurologic examination was unremarkable. Complete blood cell count was unremarkable; serum biochemistry showed mild hypercholesterolemia (6.62 mmol/L, reference [ref.] range: 2.70-5.94) and a mild increase in alkaline phosphatase (251 U/L, ref. range: 9-90). Urine was hyposthenuric (urine specific gravity 1.007) but otherwise was unremarkable. Changes were attributed to recent prednisone therapy. Thoracic radiographs and abdominal ultrasound were unremarkable. Transverse and sagittal magnetic resonance imaging (MRI) revealed a contrastenhancing, intramedullary, pyriform lobe mass adjacent to the right caudal hippocampus that was hyperintense with T2-weighted images. These MRI findings were interpreted as consistent with a glial cell tumor. Radiation was recommended to the owner but declined; conservative medical management was chosen. The dog was initially treated with phenobarbital (3 mg/kg every 12 hr) a and prednisone (0.5 mg/kg every 24 hr), b but continued to have seizures ~1-2 times a week with occasional cluster seizures. The phenobarbital and prednisone dose was sequentially increased over several weeks to a final dose of 6.5 mg/kg every 12 hr and 0.5 mg/kg every 12 hr, respectively, to maintain reasonable control. Four months after initial presentation, the owners elected for euthanasia because seizures had become refractory to medical therapy.Autopsy of the dog revealed severe generalized muscle atrophy despite the presence of abundant subcutaneous and visceral fat stores. The liver was mildly enlarged, yellow, and had several (≤1 cm in diameter) pale foci extending throughout the parenchyma. Gross lesions consistent with osteoarthritis were not identified. Removal of the brain revealed that the right pyriform lobe was mildly enlarged with a corresponding loss in distinction of cerebral gyri and sulci. Transverse sections of the brain revealed a well-circumscribed (1.5 cm × 1.8 cm × 1.7 cm), firm, yellow mass within the right pyriform lobe that extended rostrally to the level of the thalamus and caudally to the level of the rostral colliculi. The mass was attached to the overlying leptomeninges. There was compression of the ipsilateral thalamus (resulting in midline shift) and of the hippocampus and cerebral cortex (Fig. 1A). Mild hydrocephalus was present. No additional masses were found on postmortem examination. 608216V DIXXX10.1177/1040638715608216An unusual lipomatous mass in a Golden RetrieverScott et al. research-article2015Prairie Diagnostic Services ...