Caring for a Dog with Parvo?

My dog was diagnosed with parvo, but he only had vomiting and diarrhea for one day and then it stopped and the diarrhea was not bloody. It's been 3 days since he was diagnosed and he is lethargic. We have given him IVs and he got 2 shots, but I'm wondering how long it will take for him to completely get over it? Is he on his road to recovery?