it can be a symptom of it but with any dog that has a long back consider the possibility of back problems too.
I answered in your other post that our dog also had very weak legs. It is definately a symptom of Cushings. We would have to carry her outside on occasion, and she would walk around a little, pee, and then we would carry her back. It didn't happen all the time. Is the weak legs the only symptom your dog has?
I'm sorry your question got missed. I'm afraid I don't know for sure about all the different symptoms of Cushing's. But I can certainly bump up your post, so you may get an answer soon.