If it has been cold out it may be because she is cold. You migth want to call the vet anyway just in case it is something that can not be seen by human eyes,like something inside she has not been showing. When she comes in check her tempature by getting a retcal themometer putting some water based stuff on it [warm water] Slide it into the anus,or bottom 1 inch or for a large dog 3 inches hold it for 2 mins and take it out gently. That’s how you do it.