we have a 18month old labrador bitch. earlier today she was sleeping but when she woke up she yelped. and now she is not sitting down properly keeping her weight off her backside. and her tail seems to be hanging limp, she yelps when i move the base of her tail. any idea to what could be wrong with her, or is it a trip to the vets to get her checked out

Hi, Peter,
Sounds like your lab may have a high fracture in her tail. It may or may not resolve spontaneously, but I think it would be better if you got yor vet. to have a look at it for you.
Walter