Can you get a second opinion? You keep saying that they haven't got a clue - well maybe you need to take it to someone who does?
I have taken her to see two different vets... All the treatment they have given her hasn't worked... This is the last resort unfortunately... At least they are honest and have admitted they don't know and are not wasting time and money on treatments that are'nt working... X-rays on a dog her age is usually a last resort because of needing to go under anesthetic... They are at risk of dying... But they have said she will have to be put down anyway if they can't find a cause and cure... She is suffering... I am hoping that it's something that can be repaired and my dog is back to her normal self... If not at least we did everything we could to save her... I'm not ready to give up on her.
Peace