I ride an 8 year old morgan mare, who has clear issues with her right hind leg. It had began to appear that something was strange about a month and a half ago, and about a month ago things just became completely stiff. She can walk but when she does she does not bend much of her right hind leg, and it has been swollen until recently wrapping and lots of hand-walking along with light lunging in a roundpen at the walk and short periods of trotting. At times when she is walking her right hind seems to click or roll out of place, slightly like when a persons knee gives out for a slight moment, then she stops for a second and continues in her walk. She also drags her right hind at the walk. When she trots she compensates for the stiffness with forward motion. She tested negative for lyme, negative for epm. My friend said it may be a suspensory tendon injury? What are your opinions and ideas. I cannot get the video to attach because my computer does not seem to want to cooperate. I'm not sure how to explain it but this is the best I have. Ideas?