Hypothesis One: Trauma
Trauma is a likely cause of the lameness as the owner suspected that the foal 
was stepped 
on by the mother.  Being a very young foal, and underfoot a great deal this 
could easily 
happen.  I would want to know if this is the mare's first foal or not indicating 
her 
experience as a mother.  Also some information about the birth process itself 
would be 
useful.  This may tell us if the foal could have injured himself in a dystocia 
or not. If the mare and foal have been turned out or had access to other horses 
in the 
small herd, then the foal could have been kicked or stepped on by the other 
horses.  If the foal had attempted to nurse another mare or had been sleeping in 
the pasture, when the other horses decided to run around it could have been 
injured.  
If the foal had been stepped on in the fetlock joint, there could be a fracture 
of the 
bone, a 
stress on the joint or simply inflammation and pain due to the pressure.  
Bones affected could be the sesamoids (proximal or distal), Metatrasal three 
(cannon bone), or P1 (long pastern).  I also 
would like 
to know how long the foal has been lame, indicating how long the pain and 
swelling has 
been present.  If there was a small fracture, soft tissue inflammation and 
swelling would be 
likely 
sequela as the bone rubbed against tissues not usually encountered.  Also 
tendons and 
nerves could be affected primarily or secondarily leading to pain and lameness.  
The pitting edema could be caused by a tendonitis causing vascular disturbances 
and hemorrhage.  The tendonitis could be caused by an irritation of the tendon 
as a fracture caused friction of the tendon. The likely tendons affected would 
be the flexor tendons either superficial or deep as the foal is toe touching.  
This rather eliminates the suspensory as a problem.