Adenitis is a general term for an inflammation of a gland or lymph node.
Sebaceous adenitis is an inflammation of the sebaceous glands in the skin. These glands normally produce sebum (skin oil, a lipid-rich secretion) which prevents drying of the skin.
Sebaceous adenitis is an autoimmune, inflammatory, skin disease of currently unknown cause. Research is currently underway to find if there is a genetic predisposition for SA, and the exact mode of inheritance remains unknown. However, it is postulated that it is an autosomal recessive acquired condition. It has no sex-predisposition. There are two expressions of this condition, one for long or double coated breeds and one for short coated breeds, both with differing presentations.
For long- or double-coated breeds such as Poodles, Akitas and Samoyeds, the condition often presents itself with silvery dandruff which adheres to the coat, hair loss (not to be confused with moulting or "blowing coat"), a dull and brittle coat, and later on skin lesions along the back and ears as well as thickened skin and a musty or rancid odour. For short-coated breeds such as Vizslas, the condition causes facial swellings, nodular skin lesions, fine dandruff which does not adhere to the coat, and a general "moth-eaten" appearance to the coat.