Thank you guys for all the responses!
1) he was not kept on stall rest after hock was injected. When the swelling began, vet recommended no turnout but hand walking and cold hosing as often as possible. Swelling would decrease at first with walking and cold hosing, but would swell back up in literally minutes once he was back in his stall. Then vet decided turnout would be better to keep him moving. Hock has been the same size for a few weeks now since the original HUGE swelling went away.
2) he was injected with steroids and hyaluronic acid.
3) bute is an anti inflammatory as well as a pain reliever. He was put on bute to decrease the swelling, not for pain purposes.
His diet consists of grass turnout about 10 hours a day, 2 flakes of alfalfa hay twice daily, and 1.5 pounds Purina Strategy Healthy Edge + 1.5 pounds of oats in AM; 3 pounds of oats PM (he has a choke issue with regular grain, hence the high pay diet. He's been on it for about 2 years, it's the only thing that stops him from choking)
He does get Adequan injections monthly which have made a huge difference in him as well
4) I have been giving him Probios cookies daily as well as omeprazole to take care of that gut because of all the bute he has been on. Don't need any ulcers on top of all this, lol!
My trainer seems to think he is lame on the front end, and not the hind because he is head bobbing at the trot when the R front hits the ground. I'm not sure that's accurate, though. If he is lame on the R front instead, it HAS to be in the hoof (most likely an abscess, my horse is the abscess king) because his front legs are both cold and tight all the way down.