Update on our visit to the vet:
He had a temp, and his right leg was indeed swollen. She said due to the large doze of prednozone that he is on, it could be that he's contracted an infection of some sort and just has nothing with which to fight it. She said the temp was almost a good sign, although his paw and leg was also cool to the touch, which could be a sign of poor circulation and drainage ... which could result in a cardio event of some sort. She gave him a shot of antibiotic and we came home for the night.
He didn't move all night. Wouldn't eat his dog food supper, but lapped up the chicken and rice I cooked for him. Lay on the basement floor and didn't get up to go to the bathroom .... we had to physically lift him up and make him go out at one point.
My husband and I pretty much made the decision that we would spend today with him, and make the appointment for this evening. Our vet can't even talk to us about it without crying - I don't know how we're all going to get through this!
He slept through the night (I slept downstairs with him) - no messes in the house. And then of course this morning....he's frigging rallied! He ate what was left of yesterday's dog food supper, scarfed down another bowl of chicken and rice, went outside to pee (still hasn't had a bm since yesterday afternoon though) and came upstairs in the computer room to hang out with me. My husband decided to go into work, and I'm off today to hang out with Barkley.
Darn this is so hard! Maybe he's feeling better because he knows he's going to be out of pain soon ... I don't know. But now that he's rallied, I almost feel like it's not right to follow through with making the appointment for this evening.