Sebaceous adenitis is thought to be an immune-mediated disorder of keratinization with a hereditary component in some breeds. Inflammation is directed toward and destroys sebaceous glands, resulting in follicular casting, alopecia, dry skin, and changes in hair texture. Diagnosis is based on signalment, history, physical examination, exclusion of other causes of alopecia (including pyoderma and demodicosis), and skin biopsy results. Treatment includes systemic therapy with modified cyclosporine, either alone or in combination with moisturizing topical therapy.
Also see Hyperplastic and Seborrheic Syndromes in Animals.
Sebaceous adenitis is uncommon in dogs and rare in cats. The cause is unknown, but the strong predisposition of certain canine breeds suggests that genetics plays a role. The proposed pathogenesis includes cell-mediated immunological destruction of the sebaceous gland. Several mechanisms have been proposed:
a primary cornification disorder of the glandular duct, resulting in obstruction and secondary inflammation of the gland
an anatomical defect of the sebaceous gland, leading to lipid leakage and a foreign body reaction
an abnormal lipid metabolism, leading to glandular destruction
an immune-mediated or autoimmune disease directed against the sebaceous glands
Although any dog breed can be affected, the following breeds are predisposed to sebaceous adenitis:
Akita
Havanese
Lhasa Apso
Samoyed
Springer Spaniel
Standard Poodle
Vizsla
Clinical Findings of Sebaceous Adenitis Affecting the Pinna in Dogs and Cats
Typically, lesions of sebaceous adenitis in dogs and cats initially affect the pinnae, forehead, face, tail, and dorsal trunk but can become generalized. Lesions include alopecia and follicular casts (see ). Follicular casts occur when scale adheres and cements primary and secondary hairs together to form an almost pluglike structure.
Scales are casting groups of ear hair shafts in a dog with sebaceous adenitis.
Courtesy of Dr. Sheila Torres.
Long-coated dogs might have lightening or darkening of the affected hairs, as well as hairs that go from curly or wavy to straight and then become dry and brittle. Short-coated dogs develop annular areas of scale and alopecia that eventually coalesce to become larger regions of alopecia; some short-coated dogs develop nodular lesions.
The severity and characteristics of clinical signs vary among breeds. Pruritus is variable and mostly associated with secondary bacterial infection. Ocular discharge, redness, and dryness can occur, and one study found meibomian gland dysfunction in dogs with sebaceous adenitis (1).
Diagnosis of Sebaceous Adenitis Affecting the Pinna in Dogs and Cats
History and physical examination findings
Cytological evaluation
Biopsy and histopathological evaluation
Clinical suspicion of sebaceous adenitis in dogs and cats begins with patient signalment, history, and physical examination.
Cytological evaluation should be performed to look for and address secondary bacterial infection, which can also cause scale and hair loss. A deep skin scraping is necessary to exclude demodicosis.
Definitive diagnosis of sebaceous adenitis is based on skin biopsy results. Multiple areas should be sampled, including an area of "normal-appearing" hair that is submitted in a separate formalin jar or cassette.
Histopathological findings include diffuse absence of sebaceous glands, granulomatous to pyogranulomatous inflammation at previous sites of glands, and follicular keratosis.
Treatment of Sebaceous Adenitis Affecting the Pinna in Dogs and Cats
Sebaceous adenitis is incurable and requires lifelong management in the vast majority of cases. Treatment options for sebaceous adenitis in dogs include the following:
modified cyclosporine
topical therapy
vitamin A
essential fatty acid supplements
oclacitinib
These treatments might also work in cats; however, their efficacy in cats has not yet been evaluated.
All treatments are for the life of the patient to prevent relapse.
Modified cyclosporine (modified to form a microemulsion that increases absorption) can be administered as systemic immunomodulatory therapy, with or without concurrent topical therapy, at a dosage of 5 mg/kg, PO, every 24 hours (2). There is one report of a cat with sebaceous adenitis that was treated successfully with cyclosporine, 5 mg/kg, PO, every 24 hours (3).
Topical therapy can be used with or without systemic therapy. To help soften adherent scales, a mixture of 70–75% propylene glycol in water can be sprayed or used as a rinse on the patient's coat and allowed to act for 2–3 hours before bathing with a medicated shampoo containing chlorhexidine and/or miconazole. Alternatively, baby oil soaks (undiluted or diluted with water 1:1) can be applied for 1–6 hours before bathing the patient with a medicated shampoo. Leave-on moisturizers are also beneficial to further moisturize the skin and hair (4).There is one case report of a cat with sebaceous adenitis that was managed successfully with a spot-on fatty acid product (5).
Vitamin A (1,000 IU/kg, PO, every 24 hours) has shown some benefit as adjunctive therapy to aggressive topical management or modified cyclosporine (6).
Omega-3 fatty acid supplements (eg, eicosapentaenoic acid, 40 mg/kg, PO, every 24 hours, long-term with a low-fat diet) can be an effective adjunctive therapy to aggressive topical management or modified cyclosporine in some patients (7).
Oclacitinib (0.6–0.7 mg/kg, PO, every 24 hours) is not labeled for treatment of sebaceous adenitis but was used in conjunction with low-dose prednisone (0.2 mg/kg, PO, every 72 hours) to successfully manage sebaceous adenitis in a Rottweiler dog that did not respond to modified cyclosporine (8).
Key Points
Sebaceous adenitis is an uncommon, immune-mediated keratinization disorder observed most commonly in certain breeds.
Diagnosis is achieved via skin biopsy results after ruling out other possible causes of alopecia and scaling.
Treatment typically includes a combination of systemic therapy with modified cyclosporine and topical therapy with moisturizing agents.
For More Information
Marsella R. Sebaceous adenitis in companion animals. Today's Veterinary Practice. November/December 2023. Published online October 17, 2023. Accessed March 23, 2026.
Also see pet owner content regarding sebaceous adenitis in dogs.
References
Striuli G, Vandenabeele S, Nachtegaele F, Devriendt N. Correlation between meibomian gland dysfunction and sebaceous adenitis in dogs. Vet Dermatol. 2024;35(6):605-616. doi:10.1111/vde.13293
Linek M, Boss C, Haemmerling R, Hewicker-Trautwein M, Mecklenburg L. Effects of cyclosporine A on clinical and histologic abnormalities in dogs with sebaceous adenitis. J Am Vet Med Assoc. 2005;226(1):59-64. doi:10.2460/javma.2005.226.59
Noli C, Toma S. Three cases of immune-mediated adnexal skin disease treated with cyclosporin. Vet Dermatol. 2006;17(1):85-92. doi:10.1111/j.1365-3164.2005.00489.x
Lortz J, Favrot C, Mecklenburg L, et al. A multicentre placebo-controlled clinical trial on the efficacy of oral ciclosporin A in the treatment of canine idiopathic sebaceous adenitis in comparison with conventional topical treatment. Vet Dermatol. 2010;21(6):593-601. doi:10.1111/j.1365-3164.2010.00902.x
Glos K, von Bomhard W, Bettenay S, Mueller RS. Sebaceous adenitis and mural folliculitis in a cat responsive to topical fatty acid supplementation. Vet Dermatol. 2016;27(1):57-e18. doi:10.1111/vde.12282
Lam AT, Affolter VK, Outerbridge CA, Gericota B, White SD. Oral vitamin A as an adjunct treatment for canine sebaceous adenitis. Vet Dermatol. 2011;22(4):305-311. doi:10.1111/j.1365-3164.2010.00944.x
Pye C. Canine sebaceous adenitis. Can Vet J. 2021;62(3):293-296.
Pérez‐Aranda M, Yotti C, Pérez J, Ginel PJ. Successful treatment of sebaceous adenitis with oclacitinib and low‐dose prednisolone in a dog. Vet Dermatol. 2023;35(2):238-241. doi:10.1111/vde.13216
