Sebaceous adenitis

There are two expressions of this condition, one for long or double coated breeds and one for short coated breeds, both with differing presentations.[3]

• 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[3] as well as thickened skin and a musty or rancid odour.[4]
• 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.[3]

Anatomy of human skin, which shows the location of human and canine sebaceous glands

The signs of sebaceous adenitis are caused by an inflammatory disease process which affects the sebaceous glands of the skin.[5] The cause of the inflammatory disease is unknown.[6] Different breeds of dogs may have different underlying causes of the disease.[6]

Research is currently underway to find if there is a genetic predisposition for sebaceous adenitis; the exact mode of inheritance remains unknown.[7]

In Standard Poodles, sebaceous adenitis is most likely an autosomal recessive inherited disease, with variable expression.[5]

In general, sebaceous adenitis is underdiagnosed in dogs.[1] 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.[8]

Other conditions with similar presentations include: bacterial folliculitis and demodicosis, dermatophytosis, endocrinopathy, pemphigus foliaceus, zinc responsive dermatosis, vitamin A-responsive dermatosis, ichthyosis, and nutritional deficiencies.[9] As well as, superficial pyoderma, primary idiopathic seborrhea and other endocrine diseases.[8]

There is no cure for this condition.[10] Treatment is generally lifelong[3] and takes the form of bathing and soaking in mineral oils and washing with antibiotic shampoos to try to alleviate symptoms and slow the condition's progression.[11] Antiseptic and antibiotic shampoos (chlorhexidine or benzoyl peroxide) are used to manage further secondary bacterial infection.[9] For some breeds, cyclosporine or corticosteroids and immunosuppressant drugs may be effective,[3] and it is postulated, through some studies, that large doses of vitamin A given orally may result in some improvement.[3]

It has been suggested that the more aggressively one applies the topical methods of treatment, the less aggressively one needs to employ the immunosuppressant therapy. The suggestion is that this phenomenon may be due to a cyclic feedback whereby secondary infection, when not aggressively treated with topical therapy, increases and contributes to further sebaceous gland inflammation.[9]

While the condition has been seen in over 60 breeds of dog (including cross breeds),[9][12] certain breeds have been found to be more susceptible than others to sebaceous adenitis:

• American Akita and Akita Inu[13][8]
• Standard Poodle[13][8]
• Vizsla[13][8]
• English Springer Spaniel[14]
• Chow Chow[15][9]
• Samoyed[1][8]
• Weimaraner[8]
• Havanese[16]

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

• German Shepherd[15]
• Dachshund[1]
• Old English Sheepdog[15]
• Lhasa Apso[15]
• Boxer[15]
• Collie[15]
• Toy Poodle[15]
• Mixed-breeds[3]

Sebaceous adenitis has no sex-predisposition.[1] Sebaceous adenitis also occurs in cats,[8] rabbits,[3][17] and horses.[18]

Sebaceous refers to the gland which is affected by the disease. Adenitis is a general term referring to the inflammation of a gland.

•  Dogs portal

• Reichler, Iris M.; Hauser, Beat; Schiller, Irene; Dunstan, Robert W.; Credille, Kelly M.; Binder, Heinrich; Glaus, Toni; Arnold, Susi (2001). "Sebaceous adenitis in the Akita: clinical observations, histopathology and heredity". Veterinary Dermatology. 12 (5): 243–53. doi:10.1046/j.0959-4493.2001.00251.x. PMID 11906649.