Stocking up...

I was told that one of the new horses I'm working with, Houdini, stocks up sometimes. I've never worked with a horse who had this happen I
believe it has something to do with the horse's legs swelling up? Could someone please explain more thoroughly what this entails, what causes it, and what to do to prevent/help it?

Thanks in advance guys.
:]

Stocking up does refer to a condition where the horses legs, most notable the hind legs in around the fetlock area, will swell up.
It's caused by an unconditioned or inactive horse who is suddenly put to exercise.

More turn out time will help to improve his stocked up condition, and daily exercise will help to prevent it in the future.

Okay, thanks!
He's getting daily turnout and I'm just starting to work with him more, at least a couple of times a week, so hopefully it won't be a problem anymore.
:]

The less he is stalled the better. And if you have to stall him after work, cold hose his legs before you put him away.

Okay. Thanks.
He only gets stalled at night or if the weather is bad.
Other than that he's out all day.

So it would seem it was just from the stress of exercise when he's had so much time off.
The more he's worked the better conditioned he will become and this will cease to be a problem. :)