I make sure he gets at least 1-2 hours outside when he is stalled. Otherwise, he's out in the paddock(that has no shelter) 24/7.
I would suggest if you absolutely must coop him up, 1-2 hours is not enough, especially if you're not going to actively exercise him. I'd be taking him for at least a handful of walks daily if you're not allowed to let him out. But leaving him out, in company, with a rug on if there's no shelter would be my choice. Horses have spent the last... millions of years evolved to live in the open. A little rain or cold really, truly won't kill him.
He was on stall rest for almost two months .... He was getting daily exercise though. ...he was on Dex and bute
It is my understanding(could be wrong) that bute & such has no effect on stocking up because it's fluid, not inflammation. It was probably the exercise that helped avoid this problem, although I believe nutritional/systemic probs can cause them to be more or less 'prone'. I must say, if he was well enough for daily exercise, he probably wasn't likely bad enough for cooping up.
His feet are in cruddy condition due to a bad trim. Thin soles, thin hoof walls, and he's got a negative PA. ...He has poor blood flow in his hooves
Just from A bad trim? I suspect there's more to that. Poor blood flow will also be improved from good hoof function/exercise. Yes, lack of exercise & circulation will lead to stocking up.
Well, you have to think of the horse's hooves working as 4 smaller hearts
A common myth, but not actually correct.
If hooves are functioning properly, blood flow is slowed down when forced through the hoof.