sandy,
did you check fish's mouth? I shared my experience, yiu yiu got teeth "Chong" in her mouth, so she did not want to drink, even milk or water. Just show the bottle in front of her, then she cried and said "ng yiu", and brought her to see doctor, the doctor said give her some cold things to eat, and then she will be more ok and after 2 days, everythings back to normal