Article: The best and most standard test for Addison's Disease is the ACTH stimulation test. This test will gauge how well your dog's adrenal system works and show if the section of the adrenal system that is uniquely affected by Addison's Disease is damaged. The aim of this test is to take a base level blood sample while your dog is at rest to get her resting level of cortisol, which is a stress hormone. She will then be given an injection of synacthen, a hormone used to force her adrenal gland to produce more cortisol.  About one hour after this injection, another blood sample will be taken to show her new level of cortisol after the gland was stimulated. If your dog has Addison's disease, the adrenal gland will be damaged, which means it will not respond to the injection. This means that her cortisol levels will be the same before and after the injection, proving she has Addison's Disease. If your vet isn't sure about Addison's Disease, he may want to take a blood sample from your Poodle to run an overall screening panel to check her levels. He will be looking for her overall organ health, specific mineral levels, signs of anemia, and her red and white blood cell count.  Addison's Disease can cause a shift in certain mineral levels in her blood stream, including lower levels of chloride and sodium. Any significant shift in the sodium and potassium ration in her blood will help determine Addison's Disease.  This test will also help rule out other diseases and point your vet in the direction of Addison's disease. In some cases, your vet will x-ray your Poodle to help rule out other problems, such as a gastrointestinal blockage due to a foreign object, which can cause vomiting and diarrhea. It may also show her heart, which can show if there is a reduced blood volume in her heart caused by the Addison's Disease. This heart shrinkage is due to a reduced blood volume brought on by dehydration and a reductions volume of circulating blood in her system.

What is a summary?
Have an adrenocorticotropic hormone stimulation (ACTH) stimulation test. Get a blood test. Have her X-rayed.