So now for the much needed backround. I will try and give every bit of info possible, and if you guys think of anything I didn't mention, by all means, ask.
This winter has been pretty crazy, Northern VA weather. He's really only been back into serious work for the last month and a half. He's in training with me for the hunter ring, but we do quite a bit of dressage type stuff and just fitness building exercises. I'm not a professional trainer or anything of that sort, but I'm being guided by my vets and a 3 day eventer trainer from Ocala, FL.
When the weather was bad, we were barely squeezing in one ride a week, and have worked up to 3-4, sometimes 5 times a week, jumping bounces and crossrails and the occasional 2'6" vertical. So not too heavy of anything. We do lots of collection and working from behind, moving nice and forward into the bit. (His butt muscles have shown it ) I haven't been able to do any hill work because the ground has been so iffy, but if you could see his field it go very downhill, and then right back up pretty steep. (which might have contributed to the issue)
Since last summer he started "tripping" in the back, and it feels like he falls out underneath himself when I am on him, but wasn't lame from it. We had the vet out and described it and she said that he has an Upward Fixation of the Patella. (basically his "knee" locks up) I've seen horses that can't walk from it, and his was no where near that bad. Just the occasional trip. She said hillwork would be good for it and building that muscle up should take care of it.
Over the past week, the last two time I rode besides today, I was cantering over a line of ground poles and going to the right he would cross canter in between them and going around normally his gait felt smoother than usual. (all of this only going to the right, or on the right lead) I thought he was just not getting his spots and I didn't have another person to tell me it was funny looking. I feel really bad now knowing he was probably in pain :( He didn't do it at the trot at all, only the canter. And then he did it at the trot today, and even at the walk ever so slightly. He was more "trippy" than usual the past days, and I just associated it with coming back into work and because we had been doing lots of collected working trots, so I thought he was just a little tired.
(I'm trying not to leave anything out lol, so sorry if this gets long)
Yesterday we had torrential downpours all night and day. Since his field is so steep and gets muddy I wonder if he could have strained it by slipping.
Also, he got shoes put back on (all around) for the show season on April 10th. They are just regular eventer shoes, a light steel and no studs. We gave him some bute (the pills, dissolved in his food and he is so picky he didn't eat all of it) and I put some lineament on the right stifle. It appears to be that one because when my mom trotted him out he wouldn't fully extend that leg. Only about half way actually. He is field boarded, so I hope he doesn't have to be on stall rest to heal =/ but if so, I'll figure something out. He stocks up pretty bad in the back, so that's why he is on pasture 24/7.
I hope I didn't leave anything out, it took me forever to write this and think over everything lol. So if anyone has any idea what the treatment is, or if it seems like a mild sprain, pleaase let me know. I just read something that said they would never be able to be ridden again :'( it's probably a worse-case scenario, but still scary all the same. And again, if you have ANY questions regarding this, don't hesitate to ask. I also have a confo picture taken today if you think it would help and I could post the video on youtube of him trotting while I'm riding, it's short and excruciating for me to watch, because I can't believe I didn't notice that. :(