I have a 14 year old TB gelding. I've been away at school so for the past few years has only been worked in the summer months (may- august) and in the past 3 or 4 years that has been very light. Before that when he was ridden more regularly and worked harder and he needed his hocks injected yearly and also his back injected (slight changes in his back on radiographs). We did do both adequan and legend but they were at the same time as the hock injections so its hard to really note the improvement. Joint supplements never made a difference. When he is sore he gets "grumpy" and will switch leads, kick out etc.
This summer I've been doing a little more with him but have been spacing it out and limiting the schooling - just sort of having fun. We've been cross country jumping a few times and he absolutely loves it and ridden on the beach a few times and I'd like to continue to do this but feel like I should be injecting him to keep him comfortable. I start school back up at the end of August and go to school out of state so he really won't be doing anything then- so it seems silly to me to spend the money and go through the risks of injecting him if it's only for 6 or 7 more weeks! I definitely would if he was going to be ridden but he won't be.
I was thinking of just hacking him a few days a week and if I jump him, take a lesson, go to the beach, etc just give him bute and ulcerguard the night and morning before we do something.
Surpass would probably work, but its really expensive!! I had to use it on my 17 yo TB mare for a pastern injury and a tube was 80 bucks! It will only last 4 or 5 days with the amount they tell you to use but it may be worth a shot. Good luck!
If he does have changes, it's just the symptoms you will see less with riding more - injections will still benefit him, even if he's not working. They may last longer with him working less, so you may not need to maintain at the level you did before you went to school.
From what I understand there are also some newer components to the injections that are just as effective but less expensive. It's worth asking
Bear in mind that not attending to hock issues can result in more back problems over time - maybe something to think about since your guy has had some back issues as well.
I know the shots are expensive but you may well find they more than pay for themselves in the long run
What about Equithrive Joint? I just started using this on my vet's recommendation for sore stifles and I've got to say that I've been pretty impressed in the one week that I've been using it. My horse seems more comfortable already! It's about $70 per month and is a feed-through supplement. I know there is debate over whether feed-throughs work, but this one really does seem to be helping him.