Adrenal Tumors in Dogs
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.
As with other types of cancer, the causes of adrenal gland tumors are not well understood. In companion dogs, adrenal tumors are split fairly equally between adenomas, which are benign or non-malignant masses, and adenocarcinomas, which are malignant. A malignant tumor is one that tends to progressively worsen with time and, if not treated or removed, usually will result in death of the affected animal. Malignant masses typically are highly invasive, meaning nearby tissue is
If an adrenal gland tumor is not functional – which means that it is not causing the adrenal cortex to secrete abnormally large amounts of corticosteroid hormones into the dog’s bloodstream - the affected animal usually will have no noticeable symptoms of disease or discomfort. Benign nonfunctional adenomas rarely cause any significant consequences. When a tumor is functional, however; it will cause the affected adrenal gland or glands to make and release unusually high amounts
Masses on the adrenal glands are a mystery to most people, including veterinarians. Fortunately, adrenal tumors can be diagnosed and treated, or at least medically managed, most of the time. Nonfunctional adrenal tumors rarely cause harm to, or symptoms in, the affected animal. When a veterinarian sees a dog showing signs consistent with abnormally high secretion of adrenal corticosteroid hormones, she will perform a thorough physical examination of the animal. She will also take a
Nonfunctional adrenal tumors typically do not require treatment. The goals of treating functional tumors of one or both adrenal glands are to destroy or remove the affected glands if possible, and remove or destroy any sites where malignant tissue has spread. Other goals are to relieve the discomfort suffered by the dog and to restore and prolong its quality of life.The preferred treatment for dogs with functional adrenal gland tumors is to remove them surgically.