I have an older mare who sustained an injury to the front side of her left hock as a 5 or 6 year old. She is not lame due to the injury but she has a noticeable hitch when she travels down hill. Could this stiffness come from a build up of scar tissue or could it be from something else?
It very well could be a build up of scar tissue. You could have scarring of the extensor tendon and this can create what they call string halt. There may not be a whole lot you can do about it. If you’re really interested in the diagnostics you should get a veterinarian to do a physical examination to determine what it is or if it’s something that she can live with or if it’s going to get worse or not.