Histological lesions and cellular response in the skin of Alpine chamois (Rupicapra r. rupicapra) spontaneously affected by sarcoptic mange

Introduction: population dynamics of chamois (genus Rupicapra, subfamily Caprinae) can be influenced by infectious disease epizootics, of which sarcoptic mangeis probably the most severe in the Alpine chamois (Rupicapra rupicapra rupicapra). Materials and methods: in this study, skin lesions and cellular inflammatory infiltrates were characterized in 44 Alpine chamois affected by sarcoptic mange. Dermal cellular response were evaluated in comparison with chamois affected by trombiculosis and controls. Results: both in sarcoptic mange and trombiculosis, a significantly increase of eosinophils, mast cells, T and B lymphocytes and macrophages was detected. Moreover, in sarcoptic mange significant high numbers of T lymphocytes and macrophages compared to trombiculosis were observed. Lesions in sarcoptic mange were classified in three grades, accordingly to crusts thickness, correlated with mite counts. Grade 3 represented the most severe form with crust thickness more than 3.5 mm, high number of mites and severe parakeratosis with diffuse bacteria. Evidence of immediate and delayed hypersensitivity were detected in all three forms associated with diffuse severe epidermal hyperplasia. In grade 3, a significant increase of B lymphocytes was evident compared to grade 1 and 2, while eosinophil counts were significantly higher than in grade 1, but lower than in grade 2 lesions. Conclusions: this study demonstrated than an involvement of non-protective Th2 immune respnse could in part account for severe lesions of Grade 3.