My westie was diagnosed really quickly by the specialists at Glasgow Vet School. When we were referred to them by our vet they said they thought from what the vet was saying and what we were saying that it was Addisons and they would do the tests straight away. Her potassium level was 11.2 which should have been between 2.5 and 5 so was really high and they put her on a drip. They phoned us every 3 hours to let us know how she was - found out later that is because they thought they may lose her. When I mentioned it to my GP he said that must be a good vet to diagnose Addisons so quickly as it is way down the list of things that could be wrong. I would ask them to check him for this when they take blood tests. If it is Addisons it needs to be treated quickly. My vet also says that we know our pets better than anyone else so if we are not happy we should say.