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
SUBJECTIVE
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.
OBJECTIVE
Weight: 14.8 kg (32.6 lb)
Temp: 100.8 F (rectal)
Pulse: 120 bpm
Resp: Pant
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.
DIAGNOSTICS
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.
ASSESSMENT
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.
Search terms
Sebaceous adenitis in dogs, skin biopsy, affected dogs, bacterial infections, topical therapy, dogs sebaceous adenitis