Subdural Empyema in a Dog Originating From the Oral Cavity.

A 6-month-old female Bernese Mountain Dog was referred to the Auburn University Small Animal Teaching Hospital (AUSATH) for progressive neurologic signs. A subdural mass was seen on magnetic resonance imaging, occupying the entire left cerebral hemisphere. The mass was T2 hyperintense and T1 hypointense, with rightward midline shift, compression of the left ventricle, and subfalcine and transtentorial herniation. A tract of T2 hyperintensity/T1 hypointensity that was contrast-enhanced was identified extending from the last left upper molar tract to the optic sheath. These findings, along with clinical signs, were consistent with abscessation secondary to a tooth root abscess or penetrating oral injury, intracranial empyema, and increased intracranial pressure.