Multiple cartilaginous exostoses in the dog.

The clinicopathologic aspects of multiple cartilaginous exostoses (MCE) in 2 dogs were compared with those in 9 previously reported cases of MCE in dogs. Although a familial tendency is probable, there is apparently no sex or breed predilection. Only bones that developed by endochondral ossification were affected. The vertebrae, ribs, and long bones were the most frequent location of exostoses. Bones of the carpal and tarsal joints and the skull were not affected in the cases evaluated. Physical examination and radiography may provide strong supportive evidence for a diagnosis of MCE, but a definitive diagnosis must be based on microscopic evaluation of osseous lesions. Treatment is unnecessary unless growth of exostoses results in clinical sequelae. Surgical extirpation of lesions should be considered if dysfunction of the skeletal, muscular, or neurologic systems develops. The prognosis is variable, being dependent on the location and number of lesions, the age of the patient at the time of diagnosis, and the presence or absence of clinical complications.