Adrenal gland
A number of endocrine diseases involve dysfunctions of the adrenal gland. Overproduction of cortisol leads to Cushing's syndrome, whereas insufficient production is associated with Addison's disease. Congenital adrenal hyperplasia is a genetic disease produced by dysregulation of endocrine control mechanisms. A variety of tumors can arise from adrenal tissue and are commonly found in medical imaging when searching for other diseases.
The adrenal glands are located on both sides of the body in the retroperitoneum, above and slightly medial to the kidneys. In humans, the right adrenal gland is pyramidal in shape, whereas the left is semilunar or crescent shaped and somewhat larger. The adrenal glands measure approximately 3 cm in width, 5.0 cm in length, and up to 1.0 cm in thickness. Their combined weight in an adult human ranges from 7 to 10 grams. The glands are yellowish in colour.
Violet gland
In dogs, the violet or supracaudal gland is found approximately above the 9th caudal vertebra, but depending on breed it may be vestigial or entirely absent. The violet gland secretes protein and hydrophobic lipids, has wide excretory ducts, is connected with coarse hairs, devoid of cysts, and has no sexual dimorphism. In the dog and cat fancy it is often referred to as "stud tail", despite the fact that it occurs in all sexes, not just breeding males. However, for reasons still unknown the hair at a dog's violet gland tends to fall out when androgen levels are high over a prolonged time. In short-haired breeds the usually inconspicuous gland may thus appear as a noticeably sparsely haired patch, and it is this condition of the gland area that is most frequent in stud dogs.