Diseases And Histopathological Findings From Lesional Pinnae Of 10 Bats

Pinnae are vital structures for echolocation and survival in many species of bats. Pinnal lesions have been described as common in captive bats, but information on specific diseases affecting the pinnae is scarce. A collection of histological sections of lesional pinnae from 10 bats, archived by bat conservation centers worldwide, was examined to identify potential aetiologies of disease. No neoplastic changes were seen but all pinnae showed inflammation, most commonly intraepidermal pustular dermatitis, deep perivascular dermatitis, nodular and/or diffuse dermatitis, and panniculitis. All bats with deep inflammation had concurrent pinnal perichondritis and cartilage necrosis. Microbial overgrowth was frequent, and pyoderma was confirmed in two bats based on histopathological and culture findings. Although no single aetiological agent was identified, deep inflammation was common and severe, highlighting the potential detriment to affected bats and the need for future study of these delicate structures.