Sebaceous Adenitis in Dogs

What is sebaceous adenitis?

Sebaceous adenitis is an immune-mediated disorder in which the immune system causes inflammation that damages the sebaceous glands in the skin. These glands are associated with the hair follicles and produce an oily substance that helps keep the skin supple and the haircoat soft. Sebaceous adenitis tends to occur in young adult to middle-aged dogs.

There are two forms of the disease: one in short-haired breeds and one in long-haired breeds. Breeds predisposed to sebaceous adenitis include the Standard Poodle, Akita, Samoyed, and Vizsla.

What are the signs of sebaceous adenitis?

In long-haired dogs (e.g., Poodle, Akita, German Shepherd, Havanese, and Samoyed), signs may include:

• Areas of hair loss that are symmetrical on each side of the body
• Dull, brittle haircoat texture
• White scales on the skin that do not flake off easily
• Small tufts of matted hair distributed around the body
• Lesions that tend to start on top of the head and along the spine
• In severe cases (common in Akitas), the itching and bacterial infection in the hair follicles may progress to a generalized, deep skin infection, which can cause lethargy, fever, and weight loss

In short-haired dogs (e.g., Vizsla, Miniature Pinscher, Beagle, and Dachshund), signs may include:

• Patchy hair loss that gives a moth-eaten appearance
• Mild skin scales
• Lesions that appear on the head, ear flaps, and torso
• Scarring in the skin
• Bacterial infections (rare)

A skin biopsy (tissue sample sent to a veterinary laboratory) is the only way to diagnose sebaceous adenitis definitively. The pathologist will find areas of infection, inflammation, and scarring near the sebaceous glands. In advanced or severe cases, the sebaceous glands may be destroyed.

How is sebaceous adenitis treated?

Treatment is tailored to each dog and may include a combination of topical therapies, oral medications, and supplements.

• Topical therapies may include shampoos, sprays, and mousses to reduce flaking, soothe the skin, and treat any associated bacterial infection. 
• Oral antibiotics may be required but may not be used initially to try to avoid the development of antibiotic resistance. 
• Medications such as cyclosporine (Atopica®) may be used as they interfere with the immune system attack on the sebaceous glands. 
• Vitamin A, isotretinoin, and essential fatty acid supplements may also be recommended.

Treatment needs to continue for life, may change based on the pet’s response, and can be labor-intensive. Many dogs show improvement within four months, but some do not respond to treatment. This varied response is believed to be due to underlying undiagnosed conditions, such as atopy, or the inability to treat topically as frequently as needed.

Unfortunately, sebaceous adenitis is a challenging disease, as the clinical signs may come and go independently of any treatment. There are no studies to support any definitive treatment. Because a genetic basis for sebaceous adenitis is suspected, affected dogs should not be used for breeding.