Red had some slight swelling in his knee last night when I checked on him. Its very minor and he doesn't seem to be sore in or around his knee in anyway. Two of the more knowlegable people at PC poked and prodded all around with no reaction.
The conclusion is that something is sore in his hoof area and hes over compensating with his knee so he can keep the pain to a minimum which is resulting in the swelling.
We're going to wait a couple of days to see what happens with it. I'll check on him tonight and my auntie will check on him tomorrow night and then we can make the decision about whether to call the vet. I was supposed to be having a lesson with Jacqui Williams on Saturday but at this point it looks like that won't be happening.
Hopefully he'll get better soon and won't be in pain. Wish us luck.