At DELTA we use the low dose dexamethasone suppression test as a screen for Cushing’s Disease. However, sometimes we do use the ACTH stimulation test when the low dose dex test was normal and find the dog is positive to the ACTH test. The key is when the suspicion is high, continue other testing to diagnosis the problem. We recently had a dog, Black Bear, at the shelter where this very thing happened. Signs were there, the low dose dex test was normal, signs persisted; we finally ran the ACTH test and it was positive. The point is, sometimes both need to be run. I have seen the other situation occur as well, normal ACTH and abnormal low dose dex. The most perplexing cases are those where both test are negative but signs persist. Abdominal radiographs should then be taken. Some adrenal tumors show calcification and can be seen on radiographs. If these are negative, an abdominal ultrasound should then be done to see if there is an adrenal tumor. What happens if all of these tests are negative and the clinical signs are still suggestive of Cushing’s Disease? My Professor at Davis would actually treat these dogs based on clinical signs alone! A bold move to be sure, but no one is in the position to argue with him. Given the safety of the most recent treatment, Anipryl, this is not as dangerous as it once was.

We spend our lives searching for the needle in a haystack here at the D.E.L.T.A. Hospital. The decision to search is yours. By all means keep looking!