Good move. My dog has Cushing's Disease and is on really expensive medicine. He was getting lethargic and drinking more water and we at first just figured it was just age. Then he started getting into stuff when left alone, something he didn't do for 9 years. Goofy stuff like biting toilet paper rolls. We had tests run and Cushing's was confirmed. Its an adrenal gland (probably a tumor in brain or the gland itself) and makes them feel like they are starving and thirsty. This medicine made all the difference in the world. Eating and drinking normal, not getting into stuff, and gained back a ton of energy. But oh do I wish we had the insurance. His meds are 200+ a month, which is not easy for us. But he's 12, otherwise healthy, and our buddy so we find a way.