Granulomatous Sebaceous Adenitis in a Corgi Mix Dog
Felix presented for a 2 year history of progressive hairloss and dry skin. Oatmeal shampoos and itch-reducing medications such as Apoquel® and Cytopoint® were not helpful.
Christie Yamazaki DVM, DACVD
Dermatology For Animals, Oakland, CA
Felix is a 4 yr old MC Corgi Mixed Breed dog who presented to the dermatologist for a 2 yr history of hair loss and dry skin that has gotten progressively worse. His skin did not seem to improve with allergy-relief medications such as Apoquel® and Cytopoint®, nor did weekly bathing with an oatmeal and aloe shampoo. He was adopted as a puppy and had no history of skin or ear disease prior to age 2.
Weight: 14.8 kg (32.6 lb)
Temp: 100.8 F (rectal)
Pulse: 120 bpm
Dermatologic physical examination: BARH, BCS 5/9. Felix was somewhat nervous but amenable to physical exam. The trunk had generalized dry fine white scale with follicular (keratosebaceous) casting. The flanks had a mild bilateral hypotrichosis. The pinnae were similarly affected. The vertical ear canals were dry and had excessive scale with scant brown cerumen bilaterally.
Differential diagnoses included sebaceous adenitis, demodicosis, pyoderma/bacterial folliculitis, vitamin-A responsive dermatosis, ichthyosis, zinc-responsive dermatosis, endocrinopathy (hypothyroidism, hyperadrenocorticismm), and pemphigus foliaceus.
Otic cytology revealed a mild Malassezia (yeast) otitis externa, though skin cytology from the trunk failed to highlight any infectious organisms. A deep skin scrape revealed no mites or ova, though abundant follicular casts were observed. As Felix was slightly nervous, he was administered mild reversible sedation via dexmedetomidine (Dexdomitor™) IV. Four sites were selected and locally blocked with a lidocaine-saline solution, and submitted for dermatohistopathology.
The biopsy results revealed granulomas around the hair follicles where sebaceous glands normally would exist, and as seen in end-stage disease, sebaceous glands were even absent entirely in some sections. These findings were consistent with sebaceous adenitis.