I finally got Beau to a lameness specialist last week Tuesday, and that nasty idea in the back of my mind came true. This respected (and recommended) vet said he has severe arthritis in his back right hip and stifle, with a lot of fluid. At this point, steroid injections can be used to make him more comfortable, along with bute, but it's going to continue to get worse.
I certainly was not expecting that diagnosis, as I had taken him to a general small-town vet last fall who said he had a locking stifle ligament problem. Who also told me to do hill exercises.
I can tell in the last week or two that he really seems to be bothered by that leg. It's quite apparent when he moves.
So I'll keep him on his bute and hopefully get him in for his shot soon. And keep it to light riding (walking) every once in a while. Because I miss riding him, and I think he misses getting to go out!
You'd never know how bad he's hurting. If I asked him to take off running on the pattern, he would GO without a moment's hesitation. He loves it.
So that's my bad news. Phooey.