It's so wonderful. He's home and the vet said it's like night and day. Once everything she gave him "kicked in", his temperature came down 3 degrees in about 2 hours. Then, she said, he sat in the back of the cage with his eyes wide, staring at her and giving mean looks as if to say, "Don't you dare touch me anymore!" And one of the first things he did when he got home was jump up (although he didn't bounce up as easily as he used to-he's still weak) and drink water! Thanks, everyone, for your thoughts. No one at the vet's office could believe how quickly and well he's gotten. He still has a little temperature (102) and isn't too perky, but what an improvement!
Although he's an indoor only cat (someone here asked), I remember that earlier this week, I came home to find a 6 inch lizard running around our kitchen (Just like the lizards at WDW). Tigger chased it frantically around the house and could well have picked something up from the lizard or who knows what else has gotten in the house!
He's only 2 1/2, and I don't think that vet was much older (Now I sound like my grandmother). She barely looked old enough to be out of high school, never mind vet school.
So thanks all! Now just wait til DH gets home tomorrow and sees this!