Computed tomographic and magnetic resonance imaging features of canine cervical epidural dirofilariasis.

An 8-year-old neutered male Maltese dog presented with a month-long history of progressive nonambulatory tetraparesis. MRI revealed a well-defined, centrally nonenhanced, T1-weighted hypointense, extradural structure located in the vertebral canal at the level of the C5 vertebral body. CT demonstrated a hypoattenuating, space-occupying structure in the same area. Surgery revealed a long, narrow parasite in the epidural space. An adult Dirofilaria immitis was confirmed by multiplex polymerase chain reaction (PCR) assay. This is a novel report describing the MRI and CT features of cervical epidural dirofilariasis in a dog.