What to do?

My dog is backing up and then grabs her tail. Then she is running around. She is eating, going potty, and acts fine until she has to lay down. She starts crying for awhile then backs up, grabs her tail. She did not sleep well Thursday night or Friday night. What can it be and what do I need to do?

[Aleda M Cheng, D.V.M., C.V.A]

She could have an anal gland impaction or gastrointestinal parasites.  Bring a fresh stool sample to your vet to check for parasites and also have her anal glands checked and expressed, if necessary.