A 15-week-old 14.1-kg (31-lb) male yellow Labrador Retriever was referred to the Neurology and Neurosurgery service at The Ohio State University because of dullness, lethargy, and a right-sided head tilt that progressively worsened over a period of several weeks.
Clinical and Gross Findings
Results of the clinical neurologic examination were consistent with a central vestibular lesion. Abnormalities included dull mentation, intermittent opisthotonic posture and lateral recumbency, absent menace response in both eyes, decreased oculocephalic reflex in both eyes, bilateral decreased nasal sensation, and spontaneous vertical nystagmus in both eyes. Magnetic resonance imaging of the brain revealed a large, well-demarcated,