Adrenal tumors, often associated with hyperadrenocorticism or Cushing’s Disease, are lumps on one or both of the adrenal glands, located in the abdomen just above the kidneys. What causes adrenal tumors is not well-understood. In dogs, these tumors are split fairly equally between benign adenomas and malignant adenocarcinomas. Nonfunctional tumors don’t affect the adrenal glands’ secretion of hormones and rarely cause any problems. Functional adrenal tumors, whether benign or malignant, make dogs feel lousy, because their adrenal glands are secreting excessive amounts of steroid hormones into their bloodstream without any regulation. Dogs with functional adrenal tumors become weak, listless and lethargic. They aren’t hungry and they lose weight. They also become extremely thirsty. If malignant functional adrenal tumors are not treated or removed, they usually are fatal. It’s important for owners to recognize the signs of adrenal tumors so that they can get appropriate medical attention for their canine companion.