The sebaceous glands are glands in the skin that are responsible for producing sebum, a fatty lubricating oil that prevents skin from becoming dried out and brittle. In dogs with the disease known as sebaceous adenitis, however, these glands suddenly become severely inflamed and shortly thereafter are destroyed for reasons that still are not well understood. After the gland is destroyed, no sebum can be produced, and the result is incredibly dry and brittle skin that is prone to cracking and scaling.
Sebaceous adenitis is usually first observed in young adult dogs. Akitas, Samoyed, and Poodles seem to be affected the most. The disease can first be identified by the observation of dry scaly skin along the head, top and back, accompanied by severe hair loss. At its worst, sebaceous adenitis causes the formation of silvery scales and patches of thickened, desensitized skin that emits a moldy and rancid odor. In such cases, secondary bacterial infections can become a big problem. Despite this, however, sebaceous adenitis is mostly a cosmetic concern.
Sebaceous adenitis is diagnosed by observing the animal over a period of time for the persistent symptoms mentioned above (dry skin, silvery scales). If the disease is suspected, however, a skin biopsy might still be necessary in order to rule out more serious issues like skin cancer or other dermatological maladies. A biopsy is a relatively painless procedure that requires the taking of a small sample of your dog's skin tissue for laboratory examination under microscopes.
Sebaceous adenitis can only be managed through extensive, long term treatment and even then, a dog's reaction to this treatment is highly individualized. Where one dog might clear up almost entirely, the treatments can even go so far as to worsen the problem in some dogs. Nevertheless, anti-seborrheic shampoos are usually prescribed in order to remove the dry silvery scales from the surface of the skin as well as dead hair that could be inhibiting the skin's already compromised ability to "breathe". High fat dietary supplements can be useful for restoring the skin's natural oils, but if this treatment is attempted, care must be taken to counteract the added calories, or else your dog will run the risk of obesity. In the most severe cases, spraying your dog with a mixture of propylene glycol and water periodically might be necessary.
Though sebaceous adenitis isn't a very serious disease, it is a genetically inherited one, and is highly undesirable because treatments are expensive and might ultimately prove to be ineffective. As such, dogs that are known to carry this disease, or who have close relatives who suffer from it, should not be used for breeding purposes.