sprained tail

Question
what are the signs of a sprained tail & what do I do about it? It is also a possibility that it was a bite or even constipation since the 2 of them stole banana muffins while I was at work. The older dog is more of a barn dog  where the one with the problem is more of a couch dog, so getting a bite wouldn't be a surprise when food is involved. - they were both adopted. Another possibility is that when she pulled the tray down with the muffins on it, it could have hit her tail. She was experiencing pain in the tail but yesterday & today she seems like she may be constiated since she yelped when she tried to go to the bathroom.  

Answer
Tail injuries are painful.  If it was just a bruise, she will get over it. If she can raise her tail when she poops, then it is probably minor.   If not, then it could be fractured or even have nerve damage.  If it is a bite wound, then it may open up and drain fluid. Have your vet check it if it does not resolve on its own.