Help! i have a 8 month old puppy and he has been throwing up for almost 24 hour?

he has a bad habbit of eating stuff out in the courtyard, but we try to watch him closely to make sure that he doesn't, including clearing out his mouth before bringing him back into the house. he is vomiting mucousy, hy, at first, there was a little dog food and part of a rawhide bone, but he hasn't eaten or drank anything to speak of since last night. i have been giving him a little pedialyte every once in a while so that he doesn't get dehydrated.... Help, he is my baby... i don't know what else to do.....