Hypothesis 1: 

Traumatic origin of right tibial and left femoral fracture:

Right Tibial fracture:
There is palpable instability of the right tibia.
The joints of the right hind leg appear to be normal.
The tibia does not appear to be continuous in the midshaft area, likely location of tibial 
fracture.

A complete fracture of the tibia in the midshaft region induced by the hit by car provides an 
explanation for the clinical signs presented above.  Since the hip, stifle, and hock joints 
appear normal during the orthopedic exam it is unlikely that there is any damage to the 
joints.  Acute edema is likely to be noted in the region of the midshaft tibia in response to 
the tibial fracture  and corresponding soft tissue damage.



Left Femoral fracture:
The upper left hind leg is very swollen and bone continuity of the upper femur is suspect 
because of abnormal movement of the limb and occasion crepitation.  
The source of these abnormalities could not be precisely located to the femur, the hip joint 
or the pelvis.
The bones and joints of the remainder of the leg appear to be intact and normal apart from 
diffuse subcutaneous fluid accumulation.  

A complete fracture of the femoral head or femoral midshaft induced by the hit by car 
provides an explanation for the clinical signs presented above.  Abnormal limb movement 
in the area of the hip and crepitation during limb movement could be caused by midshift 
rubbing against midshaft or femoral head rubbing against femoral neck.  The bones and 
remaining joints in the leg appear to be intact and normal so it is unlikely there is any 
damage to these areas.  The diffuse subcutaneous fluid accumulation is probable due to the 
femoral fracture and the corresponding inflammation accompanying it.  There is likely mild 
soft tissue damage on the entire hind leg supported by the fact that there is limb edema.

Due to the severe nature of this hit by car incident it is likely that there could be renal, 
spleen, myocardial, or thoracic cavity damage (pneumothorax).