Primary Idiopathic Seborrhea
Primary idiopathic seborrhea is the most common chronic keratinization (dermatitis) disorder of dogs of genetic origin. The onset of signs is usually before 2 years of age. Depending on the breed, clinical signs may range anywhere from dry scaling (seborrhea sicca), to greasy scaling (seborrhea oleosa), to scaling and greasiness with inflammation and itchiness (seborrheic dermatitis), to any combination of these clinical abnormalities.
Seborrhea sicca is seen primarily in the Doberman Pinscher, Irish Setter, German Shepherd Dog, and Dachshund. Dogs affected by seborrhea oleosa will have malodorous, greasy skin and hair coat with accumulations of brownish-yellow material that adheres to the hair and skin. Neck, and feet are most severely affected. Frequently, there is a concurrent ear disease with excessive buildup of earwax. Breeds predisposed to seborrhea oleosa include the Basset Hound, Cocker Spaniel, English Springer Spaniel, Labrador Retriever, Shar-Pei, and West Highland White Terrier. Dogs with seborrheic dermatitis have malodorous, greasy skin and hair coat, along with moderate to severe inflammation, bacterial folliculitis, Malassezia dermatitis, itchiness, and inflamed skin plaques. The most commonly involved areas are the external ear canals, ear skin, neck, and chest. This chronic disease cannot be cured, only controlled. The life-long therapy will require special grooming, frequent bathing in medicated shampoos, and treatment of recurrent yeast and bacterial infections.4
The diagnosis of primary idiopathic seborrhea is based on age, breed, history, and clinical tests. Clinical signs vary but tend to worsen with time. Mildly affected dogs show scales around the nipples, lip folds, and external ear canals. More seriously affected animals have lesions in other body fold areas. Mild seborrhea sicca cases will respond to frequent applications of moisturizing shampoos and rinses. Seborrhea sicca may respond partially to systemic essential fatty acids. Acitretin (1 mg/kg orally every 24 hours) has been an effective therapy for some idiopathic seborrhea problems of Cocker Spaniels, English Springer Spaniels, Irish Setters, and Golden Retrievers. Mild to moderate shampoos containing sulfur or salicylic acid may be needed to remove heavier, dry scales. Stronger degreasing agents (benzoyl peroxide, tar, sulfur, selenium sulfide) are needed to control the greasy scale, crust, and odor associated with seborrhea oleosa. Contact with the shampoo (completely lathered) must occur for at least 10 minutes. For animals with an extremely thickened accumulation, bathing with D-Basic before a medicated shampoo is used may prove beneficial and may be sparing of the more expensive products.3 Systemic antibiotic may be prescribed if there is a secondary bacterial infection. Maintenance ear cleansing is imperative and identification and treatment of ear disease is very important.2
- Skin Diseases of the Dog and Cat. Tim Nuttall, Richard G Harvey, Patrick J McKeever
- Clinical Medicine of the Dog and Cat. By Michael Schaer DVM DipACVIM ACVECC
- Small Animal Clinical Pharmacology and Therapeutics. Dawn Merton Boothe
- Small Animal Dermatology. Karen Moriello DVM, ACVD