Hypothesis 3

The original trauma was probably from the difficult birth since the swelling has been 
present since that time.  The calf was too large to be born without assistance.  The 
obstetric chains were placed on the distal metacarpals and distal second phalanges of both 
front limbs.  In the process of pulling, the distal physis of the fourth metacarpal of the left 
forelimb could have been damaged, thus stopping the growth of this bone at its distal end.  
As Mc3 continued to grow on the medial side of the distal canon bone, the bones distal to 
the fetlock joint were forced to bend laterally, thus the valgus deformity of the fetlock.  
This supports why the instability (from fracture) is at the distal end of the metacarpal, 
why the crepitation (from the fracture) is in the area of the instability, and why the 
metacarpal phalangeal joint has limited range of motion.  Neither the bandage nor the 
cast would prevent this growth.  The limb has had 3 months to grow, and the deformity 
was noticed not immediately, but rather after having been bandaged and casted, 
supporting growth of the limb leading to deformity, not malalignment immediately after 
trauma.
The superficial wounds could have resulted from chain trauma or pressure from the 
bandages.  Infection could have entered these wounds causing osteomyelitis as described 
in hypothesis 1.  
The non-weight bearing lameness is the result of pain, possibly from this infection, 
possibly from inability to use the joint (mechanically inhibited by fracture and swelling).
The tension of the skin over the dorsum of the foot to the toes could either be due to 
contracture of healing following skin sloughing from bandaging or due to immobilization 
of ligaments in a tight position for 3 months Ð these ligaments could be stretched.