Something’s wrong with your dog but you’re not sure what. She seems listless, her eyes have lost their spark, and she just seems “off.” You might notice intermittent muscle weakness, tremors, and an inability to jump into the car or onto a sofa. Or your dog frequently ignores her dinner, vomits, or has diarrhea. These vague symptoms, which may improve and then return, could stem from a dozen canine illnesses – or they might point to Addison’s.