Parvo?

my puppy, Sarge,  is 7 to 8 months old.  He started acting funny saturday, he wasn't playing or running around with our other dog.  Sunday he didn't eat much or drink much but he did eat.  Monday he had not ate anything, drank some water but threw up right afterward.  I took him to the hospital and they said he tested mildly positive for Parvo.  The admitted him and started treating him with an IV and antibiotics.  He has had diarrhea and vomitting since then.  This morning he's had a very little diarrhea and some vomitting.  The dr. at the hospital is still treating him for Parvo, could this be something else?  Could he have a blockage somewhere?  He had gotten into the trash friday night after dinner, that night I had fixed chicken for dinner.  I'm not sure what he ate from there.  If this is Parvo, how soon should I be seeing signs of improvement?  I believe he is no longer running a fever, and yesterday I was able to get him to take two tiny sips of a liquid they were giving him.

[have 2 kids]

Has your dog been given his vaccinations?  If he recently had a live parvo injection (within a week) it is possible he is testing positive from that.   If he hasn't had the vaccine recently and tests positive then he definately has parvo.