Well I now have my doggies' results. All blood tests came back normal. Having said that she is still rather depressed & lethargic looking. She does have a dodgy liver and my vet thinks mabe it was a pancreatitis episode. However she is to have another test for Cushings in 2 to 3 months as apparently it does not always show up immediately in the early stages.
On Dec 5th she is to have a bile acid test and Kelly Louise, she will have her thyroid tested at that time. Thank you for that suggestion, and no she has not been tested for that previously.
She is currently on a strict diet, canned L.D. Prescription food which she does not really like . This is helping to get her weight down as she eats smaller meals. The insatiable thirst has gone , as has the weeing inside.
I guess there are some positives in all of this but the diagnosis is still rather inconclusive.
Thank you all for your interest , I will let you know how things unfold.