Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

672 Small Animal Radiolo g y and Ultrasono graphy
Fig. 6-6 A 9-year-old male English
Pointer with a 4-week history of
stumbling, with neck pain apparent
on physical examination. A, The lateral
radiograph revealed lysis of the
entire C6 vertebra, most apparent in
the pedicles and laminae. The myelogram
revealed a ventral deflection
of the dorsal subarachnoid space
(white arrow). B, The ventrodorsal
view revealed loss of the left pedicle
and deviation of the subarachnoid
space to the right (white arrows) at
C6. These findings indicate that the
subarachnoid space is pushed in
more than one direction by mass(es)
external to the dural tube. This indicates
a complex extradural mass.
Diagnosis: Osteosarcoma of C6 with
tumor mass in the left and dorsal
portions of the extradural space.
A
or so-called screw-tailed breeds such as the English Bulldog, Boston Terrier, or Pug (Fig.
6-9). Hemivertebrae in the thorax may be associated with rudimentary or fused ribs. 40
These vertebral abnormalities usually are without clinical significance; however, some
instances of spinal cord compression associated with hemivertebrae have been
reported. 41-43 Trauma to the vertebral physis may cause a growth deformity that
appears identical to a hemivertebra. This can be symptomatic if cord compression
results from the abnormal growth of the vertebral body. A myelogram usually is
required to determine if cord compression has occurred secondary to the vertebral
deformity. 41
B