we have a four month old puppy that was neutered on Thursday. having a hard time getting him to eat - but honestly have had a hard time getting him to eat since we got him three weeks ago. took him back to the vet yesterday and everything looked fine, did get him to get a little of the dog food the vet gave me last night, but not very much. I boiled chicken this morning and was able to get him to eat some of that, but nothing since then. all he wants to do is sleep/lie around. he doesn't seem to have any energy. I don't remember having this problem with our other dogs when they were spayed/nuetered. do I need to take him to the ER vet today or do you think it is ok to wait until Monday? he is drinking water ok, and seems to be peeing a lot. I thought maybe bladder infection, but I know it isn't common in boys. any advice ????