Spinal cord compression caused by osteocartilaginous exostoses of the spine in two dogs

Two dogs, one 4 months old and the other 1 year old, had histories of progressive posterior weakness. In both cases, there was severe asymmetric proprioceptive loss but appreciable preservation of strength. Benign, cystic expansile lesions involving the facets and lamina of the thoracic spine were observed radiographically; a single lesioons was demonstrated in the other. Examination of biopsy speciments taken at the time of laminectomy revealed the lesions to be osteocartilaginous exostoses (osteochondromas, ecchondromas, exostoses). The progress of dogs 1 and 2 has been monitored for 1 1/2 years and 9 months, respectively. Dog 1 has no weakness or proprioceptive loss; dog 2 has a mild proprioceptive loss in the right hindlimb.