Problem with the tail

Question
Hi!
I have a 11 month old American Eskimo/Maltese dog that keeps chasing her tail, biting it and pulling it with her teeth quite often and she is usually whining when doing so; as if she were annoyed by it or in pain. Most of the time if anyone touches it, it would take her attention immediately and she would start this behaviour. Is there any reason to why she does it, or is it a compulsive disorder as I've read on the internet?
Thank you for taking the time to read my question!

- Nadine

Answer
Sometimes it is compulsive, but sometimes it is rectal pain or cramps.  Often the tail itches.  Ask the vet to give one shot of a steroid to see if it goes away.  If it does, then it is something that is painful.  If not, then it is probably a behavior.