About three weeks ago, my 24 y.o. TWH gelding, Mozart, came in with what appears to be a slight injury from a kick on his side near the girth area. It wasn't a big deal and didn't seem to be bothering him much. The swelling went down the next day and everything seemed to be just fine.

Fast forward three weeks...the swelling is back. It's not quite as swollen as before, but it IS swollen and while it's not bothering him a great deal, it's bothering me.

I have a call in to a vet, but since it's not an acute emergency, it may be tomorrow before he gets out. In the meantime, does anyone have any thoughts about whether this could be something serious?