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&#x2009;years in Akitas and 5.5&#x2009;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&#x2009;<&#x2009;0.0001). Epidermal hyperkeratosis was observed in all cases in both breeds, yet poodles exhibited a more severe form (p&#x2009;=&#x2009;0.0019). Follicular infundibular orthokeratosis was observed in most cases and was significantly higher in poodles (p&#x2009;=&#x2009;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.