Comparative Histopathological Characterisation of Sebaceous Adenitis in Affected Poodle, Poodle-Related Breeds and Japanese Akita Dogs: A Retrospective, Blinded Study.

Abstract

Background: Sebaceous adenitis (SA) is a well-documented disease in poodles and Akitas. However, no comparative histopathological studies have been conducted across breeds affected with this condition.

Objectives: Herein, we describe the histopathological features of SA skin lesions in 20 Akita inu and 13 poodle dogs.

Animals: Inclusion criteria were Akita inu or poodle breeds with clinical signs consistent with SA and confirmed with histopathological lesions.

Materials and methods: Histopathological features of Akita inu and poodle dogs diagnosed with SA were reviewed and compared on archived skin biopsy specimens.

Results: The average age of dogs diagnosed with SA was 4.6 years in Akitas and 5.5 years in poodles. Sebaceous glands lacked in 15 of 20 (75%) biopsy specimens in Akitas and eight of 13 (62%) biopsy specimens in poodles. Perifollicular inflammation was generally present in both breeds, varying from mild, predominantly lymphoplasmacytic to moderate or severe pyogranulomatous inflammation. Akitas show a higher degree of perifollicular inflammation (p < 0.0001). Epidermal hyperkeratosis was observed in all cases in both breeds, yet poodles exhibited a more severe form (p = 0.0019). Follicular infundibular orthokeratosis was observed in most cases and was significantly higher in poodles (p = 0.04). Other commonly observed lesions were superficial dermatitis, perifollicular fibrosis and follicular fronds.

Conclusion and clinical relevance: Akitas exhibit more intense inflammatory changes than poodles, while poodles display more prominent hyperkeratotic changes and follicular fronds. These breed-specific features of SA warrant further investigation, as they may offer valuable insights into the pathogenesis of the disease.