Use of Magnetic Resonance Imaging in the diagnosis of spinal empyema caused by a migrating grass awn in a dog.

Abstract CASE HISTORY: A 13 kg 3.5-year-old male neutered Cocker Spaniel presented with a 6-day history of deteriorating hindlimb paresis. Approximately 10 weeks previously the owner reported removing a large number of barley grass seeds from the dog's coat and ears. Eight weeks later the dog was treated for pneumonia, based on clinical findings and thoracic radiographs. In the 4 days prior to referral the dog had a decreased appetite, was lethargic and appeared unable to urinate voluntarily.
CLINICAL FINDINGS:
The dog was bright and alert but unable to walk. Upper motor neuron signs were indicative of T3-L3 spinal lesion. Using magnetic resonance imaging (MRI), an abnormal low signal linear structure within the left T12-T13 neural foramen extending to the left lateral aspects of the thoracic spinal cord was detected, consistent with a foreign body. A left T12-T13 lateral hemilaminectomy was performed and a grass seed removed from a tract extending caudally from the T12-13 space, dorsal to the lumbar transverse processes and the rib head. The dog made a rapid recovery after surgery with full resolution of clinical signs.
DIAGNOSIS:
Spinal empyema caused by a migrating barley grass awn (Hordeum spp.).
CLINICAL RELEVANCE:
Advanced imaging using MRI can bea valuable method for localising foreign bodies prior to exploratory surgery. Animals presenting with neurological signs should have foreign body reactions included as a differential diagnosis.