Hello,
it all depends on wether or not the growth plates on his bones are already fused or not.
If not, there's potential for more growth over the next 2 years.
But I wouldn't poor feed into him now. Is he now large enough that a saddle will fit him? If yes, I would take the chance, because it's likely that he will grow some more.
Next I would do a full work-up: blood, fecal tests, worming, getting him on a good mineral feed and adding a bit of grain - depending on the results of the work-up.
If you want to invest that much time, money and effort is up to you.
it all depends on wether or not the growth plates on his bones are already fused or not.
If not, there's potential for more growth over the next 2 years.
But I wouldn't poor feed into him now. Is he now large enough that a saddle will fit him? If yes, I would take the chance, because it's likely that he will grow some more.
Next I would do a full work-up: blood, fecal tests, worming, getting him on a good mineral feed and adding a bit of grain - depending on the results of the work-up.
If you want to invest that much time, money and effort is up to you.