Osseous metaplasia of the spinal dura mater in a Great Dane.

A 4-year-old male Great Dane with a history of progressive ataxia and associated bilateral atrophy of the muscles of the shoulder was found to have severe osseous metaplasia of the spinal dura mater. These dural ossifications were directly associated with underlying spinal cord degeneration. No other condition could be identified that would account for the pathologic changes in the spinal cord. The lower motor neuron (LMN) type weakness was in contrast to the upper motor neuron (UMN) type weakness said to occur with this disease and recently reported to be due to primary degenerative myelopathy.