Ugh, yup. I am totally in the same boat, although I have two.
My older gelding I purchased for cheap when I was in college-a small 12 year old ottb that hadn’t done much for a few years (jumping some teeny jumps with a teen eq rider). I did a PPE, vet noted he “may need hock injections eventually”, brought him home and the minute he entered full work he felt horrendous. Basically trantering anytime I asked for any collection in the trot. Had my vet out, found out that the reason the PPE vet said he may need hock injections is because his hocks are fusing (the PPE vet never used this terminology with me so I had no idea, AND they had mislabeled the radiographs on top of that. I was very unimpressed.) We did the hock injections, started dressage work, and he was doing really well. Then in the spring started acting funky again. Found a bone spur in his neck causing neck arthritis-so we injected his neck. Over the course of the next few years, it was one thing after another. The back got sore, the SI needed injecting, the front right went lame and we found navicular, one spring he came down with headshakers so he has to stay on magnesium to curb it. He was an incredible jumper but at shows he wouldn’t want to jump. We would go xc schooling and he would jump the training height things with no problem. We would go to a beginner novice show and he would always have refusals. Then, when we tried to show more consistently, he would go lame (I assume he couldn’t handle all of the varied terrain). Finally, when he was about to turn 16 I threw in the towel with him. I love this boy to death and know him like the back of my hand, so I kept him. I was planning on moving him somewhere cheaper to afford a second horse, but a rider at the barn inquired about leasing him and luckily it has worked out perfectly. She doesn’t have any aspirations to show him, and she understands he may have days where he feels a little stiffer than others.
My second horse, I was finally out of college with a “big girl” job and was able to spend five figures (a low! five figures) with the help of my boyfriend. I did a decent PPE with drug test, rads, etc. and the only thing of note was he had very mild hock arthritis and needed a change in shoeing. That was totally fine with me. He also cross cantered on the lunge to the left, but he had no muscle at the time of purchase having sat for a while and was really weak so I took the chance that it was a strength issue. It has now been a year and a half of trying to figure this horse out, because he has been incredibly difficult. I have done so much to try and make sure he is comfortable-I’ve looked into hocks/back/neck/stomach/SI/feet/coffin joints/stifles etc and nothing has worked. I am crushed, as I have been trying to event for 11 years now and still haven’t been able to. There are a couple more things I may try with this horse but otherwise I don’t know what to do. I can’t afford a third horse, but I also can’t even afford the purchase price of a new horse if I were to find a home for this guy, because I clearly wouldn’t be able to sell him for any amount of money. I suppose I could rehome him, and get something off the track for cheap…but I am scared that it will just be another horse with hidden issues.
I completely, completely understand you, and I have written a similar post myself (while also sad and salty!) so I totally get it. I am going to keep trying for a little bit longer-but it is so, so hard, especially seeing other people with just one horse moving right on up the levels with no issues.