Since he was 4 years old, he was ridden almost every single day (with the winter off) until the past 2 to 3 years, when I have been gone for graduate school. He's basically just been on "pasture rest" for that time.
The few times I did ride this past summer, he did a weird mis-step with his hind right foot. Some days it was awful (doing this on every single step at the walk or trot) and some days it was so-so. Instead of picking his right hind hoof up to step on it, he is catching his toe and letting it rock over, so that he is then stepping on his own bent-over ankle. Since then it has progressed and he now compensates for it while walking, by swinging his leg outward.
No swelling, no tenderness, no heat, and no physical signs on his right leg. I can tell it is starting to bother him (whereas this summer he acted like it was not happening and carrying on his merry way), because he doesn't even like to left his left foot because it forces his right leg to bear all the weight on the ground. He will pick up his right foot no problem.
Plus, he still runs, bucks, and plays in the pasture like nobody's business, especially since he's got 2 colts to play with and run around with. Earlier this summer, he didn't seem to be phased by it, but now you can tell he is compensating.
If I think back now, I think this has actually been going on for years, but it was always very rare for it to happen, so that I took it as him being clumsy (which he kinda is) or stepping in a hole, over all these years. Now that he hasn't been ridden or kept in shape the last 2 or 3 years, it's really gotten bad.
My mom took him to the vet for me in October-ish. Just two small town vets, nearest to us. My mom said that they said it is a stifle problem in his back right leg where the ligament is essentially "locking up" on him which renders him unable to fully complete a step. So that's why he's coming down on his folded ankle, because he is not able to fully extend his foot.
The vet said that exercise is the best treatment; especially hill climbing. If the muscles and tendons and ligaments can tighten up by being in shape, then it will be less likely to lock up on him.
He also mentioned that surgery is a possiblity, but he does not recommend it at this time because it's not a 100% sure fix, and he doesn't have it bad enough to where he would consider surgery.
I was home for a couple days last week and we took some video of him moving around. I am going to take him to another vet in May that is more specialized for this sort of thing, before I start riding him on a regular basis after I graduate. Plus, I just want another opinion on anything I can do for him.
So any commments on what you think may be wrong or what can be done to treat it, I would really appreciate. I don't want to give up on him! Hopefully, I can also get him to both a chiropractor and a massage therapist in May, along with another vet visit.
These first 3 are me trying to get the video myself ... not the greatest.
Then I had my mom lead him around for me.