Inflammatory Skin Disease in Dogs

Sebaceous Adenitis in Dogs

Sebaceous adenitis is a rare type of inflammatory skin disease that affects the skin glands of young and middle age dogs. This condition most commonly affects Poodles, Akitas, and Samoyeds, although other breeds -- and some cats (rarely) -- can also be infected.

Symptoms and Types

There are two primary types of sebaceous adenitis. One type occurs in long-coated animals, and the other type occurs in short-coated breeds.

The signs and symptoms of sebaceous adenitis in long-coated breeds include the following symptoms:

• Alopecia
• Odor along the hairline
• Small clumps of matted hair
• Casts forming around the hair shaft
• Hair that becomes dull and brittle or coarse
• Intense itching along the hairline and scratching
• Bacterial infections along the hair follicle
• Silver-white scales on the skin
• Clusters of skin lesions that form in certain areas of the head

Among short-coated breeds the following signs and symptoms are most commonly reported:

• Alopecia -- often occurring in a circular pattern, or diffuse and spread out along the hairline
• Mild scaling of skin along the head, trunk and ears of the dog’s body
• Secondary bacterial infection along the hairline, although this is less common among short-hair breeds

Causes

The exact cause for sebaceous adenitisis is unknown; researchers are currently studying the causes.

Diagnosis

Your veterinarian will rule out other conditions before confirming a diagnosis of sebaceous adenitis. Some other causes for similar symptoms include the following conditions:

• Primary seborrhea -- a skin disorder known as a keratinization disorder, a process whereby the dog’s body produces a substance known as keratin. This disorder can also cause flaking and itching of the skin.
• Demodicosis -- an overgrowth of skin mites that can cause itching, hair loss, and inflammation
• Dermatophytosis -- a fungal infection that causes itching and flaking
• Endocrine skin disease

Diagnostic procedures used to test for sebaceous adenitis include skin scrapings and endocrine function tests, which usually return as normal. Skin biopsies may also be taken for lab testing. Pathologic testing may reveal inflammatory reactions of the sebaceous glands -- the fatty glands found in the hair follicles, which provide oil to the hair and skin.

With long-coated breeds, there may be raw and blistered skin, and even complete loss of the sebaceous or oil producing glands during advanced stages of the disease. Some animals may show evidence of advanced sebaceous adenitis, with excessive fibrous tissue or destroyed hair follicles, although this is very rare.