Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

484 Small Animal Radiolo g y and Ultrasono graphy
Fig. 4-7 A 2-year-old female Australian Shepherd was
hit by a car and unable to bear weight on the right rear
limb. There is a comminuted fracture involving the midportion
of the right tibia. A large butterfly fragment is
separated from the lateral cortex of the tibia. There is
cranial and lateral displacement of the distal tibia fragment
with slight overriding of the fracture fragments. A
thin fissure fracture extends distally in the distal tibia
(arrows). Fractures of this sort should be noted carefully
on preoperative radiographs. There are multiple fractures
of the fibula with fracture lines at three sites.
Diagnosis: Comminuted tibial fracture and multiple
fibular fractures.
Fig. 4-8 A 3-month-old female mixed breed dog was stepped
on by the owner and has not been bearing weight on the left hind
limb since that time. There is an incomplete fracture involving
the proximal one third of the left tibia. There is also a folding
fracture involving the proximal fibula (arrows). The overall bone
density appears decreased and the cortices are thin. The thin cortices,
poor bone density, and folding-type fracture are indicative
of pathologic fractures due to secondary hyperparathyroidism.
This dog’s diet was predominantly meat, and therefore a diagnosis
of nutritional secondary hyperparathyroidism was made.
Diagnosis: Greenstick and folding fractures. The dog had an
additional greenstick fracture of the left femur.