A 12-year-old Maltese terrier was evaluated for progressive tetrapares
is and neck pain, On radiographs, there was a periosteal reaction invo
lving the fourth cervical vertebra, Myelographically, there was extrad
ural compression of the spinal cord associated with the lesion, The do
g was euthanized and necropsied. Histopathologic diagnosis was paroste
al osteosarcoma of the vertebra.