Puppy born 4/19/11, he is sick! Any one know how to help?

My girl had her puppies on the 19th... She had 4, one was still born & the other three made it. Well we have been noticing the only boy in the group... He still is the size he was the day he came out, he doesnt eat, he had runny poo, his skin seemed like he was dehydrated. He also cant move around like the other two & he doesnt whine really loud like them either. Tonight, we checked on her & she had him away from her & the other two & when he would attempt to get to her, she would push him back. We even tried helping him onto her nipple so he could eat, and she kicked him off... So, I decided to try to care for him. Right now I have him in a little plastic box wrapped in a wash cloth & in a big fleece blanket, with a warm water bottle beside him. He wont eat a bottle, Ive been using a syrange (sp?) to try to give him formula & sugar water. I clean him with cotton dipped in warm water. Anyone know of anything else to do for this baby? Any ideas on feedings?? Any help will help alot!