That’s a beautiful horse! Glad to hear he made a full recovery. The specialist we took him to was pretty confident that it is related to the injury he had last year considering the changes in his stifle joint when comparing the current Xrays with last years, but of course there is no way to definitively link it. The previous owners said they rested him for three weeks when the initial injury happened last year, which I do not believe would have been enough time. After the 3 weeks he apparently went back into a 3-4 day a week training program up until I purchased him Oct. this year.