Originally Posted by
Steaphany
First and foremost, Was the image captured in RAW ?
If this was an in-camera JPG, the file probably lacks the necessary detail to recover the shadows or fill in the obscured area sufficiently with a fill light adjustment.
Was this a single frame of several shot in rapid sucession ? If that is the case, you may be able to recover obscured details by blending multiple exposures when the region obscured by the fence shadow covers different areas from frame to frame.
One possibility is to crop the head, shoulders and upper body just above the fence shadow.
BTW, having been bashed by Horses... Ouch.