Internal injury, or a virus?

[Think]

Hi all.

We've had Peanut, a neutered male American Shorthair, for just shy of four months now. He's a playful little guy that acts much like a dog. He's about 20 weeks old.

Anyway, we just recently got another American Shorthair, Cinnamon, from an acreage that was giving away free kittens. Cinnamon is an intact female with a beautiful calico coat. She's about 25 weeks old.

Yesterday, 27 October, my wife and I woke up and were greated by Peanut in the kitchen. We keep Cinnamon separated from Peanut, but they have closely monitored face-to-face time when we're around. Anyway, my wife picked Peanut up to give him a scratch behind the ears. As she was holding him, Peanut jumped out of her arms and landed hard on the lenolium floor. He seemed to land a bit on his side, but he got up and seemed just fine. I proceeded to get dressed and left the house for work.

My wife called less than 15 minutes after I left (about 45 minutes after he fell) saying that Peanut was at the Veterinarian and was to be there overnight for observation. He had started bleeding from his nose and his eyes were out of focus, but she wasn't sure exactly what happened because she had stepped into the bathroom. She immediately called our Veterinarian, which thankfully is open Saturday mornings, and rushed him there. The doctor said, after examining him and listening to his breathing, that he had sustained some sort of internal damage, and that the only way to really tell what was going on was to keep an eye on him and see if he heals up. He said that we could get x-rays, but regardless of what we chose to do it would have to wait at least until Monday, probably later.

Fast-forward to Sunday evening. We retrieved Peanut from the Veterinarian this noon after his over-nighter, and we were told that he was sluggish and sleepy. Since getting home, he's vomitted three times, and is refusing water. I called the Veterinarian, and we were instructed to take away his food and give him only water. He's sneezing every now and again, and each time he does I about have a heart attack from my nerves. He hasn't sneezed up any blood since yesterday. He is very, very sluggish, and he's been in a daze since returning home. He's usually very playful, and almost puppy-like in his interactions with me and my wife.

So, here's my question: Do you think Peanut was injurred internally by his awkward landing, or could he have picked up some sickness from the new, healthy kitten, Cinnamon?