I have a new puppy, that I got 2 weeks ago. Today she woke up, ate this morning and has had diarrhea today along with continual mucus coming out of her rear end. She has not drank any water or eaten a thing since this morning. And she has slept all day. Her stomach is continuing to gurgle and she has gone from 4.2 pounds to 3.4 pounds in a day. What could this be and should I be worried??