Sebaceous adenitis

In canines, sebaceous adenitis, or SA, refers to the autoimmune disease found in some breeds of dog and more rarely in cats, rabbits and horses. It is an uncommon, idiopathic skin disease, characterised by an immune response against the dog's sebaceous glands (glands found in the hair follicles in the skin dermis), which can lead to the destruction of the gland. It was first described in veterinary literature in the 1980s.

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.

Sebaceous refers to the gland which is targeted by the immune system of affected animals. Adenitis is a general term referring to the inflammation of a gland.

While the condition has been seen in over 60 breeds of dog (including cross breeds), certain breeds have been found to be more susceptible than others to sebaceous adenitis:

Breeds also mentioned in scientific literature as having some susceptibility include:

There has also been mention of the condition in cats, rabbits and horses.

In general, SA in canines is underdiagnosed. It has however been described in more than 60 breeds of dog as well as mixed breeds. Diagnosis confirmation requires multiple punch biopsies analysed by a dermopathologist who will comment on the condition of the sebaceous glands, revealing granulomatous or pyogranulomatous inflammation surrounding the sebaceous glands or even complete destruction of sebaceous glands.

...
Wikipedia