Pathological and parasitological examinations of samples from dead animals
All of the dead gorals and 1 dead serow had obvious mite-induced cutaneous lesions, characterized by bleeding crusts, hyperkeratosis, cutaneous chapping and alopecia, on all four legs and the head and trunk (Fig. 3). The gross records of cutaneous lesions from the dead animals are shown in table 3. Sarcoptic mange mainly occurred on all four legs and the head, especially on the lips and joints (Fig. 3). This would severely impact eating and walking in these animals (S4).
Histopathologically, mites in the epidermal layer were observed in all goral and serow samples but not in samples from the other animals in this study (Fig. 4A, Band C). Typical histopathological lesions were characterized by hyperkeratosis, hyperplasia and papillomatosis in the epidermal layer; squamous epithelium degeneration; and inflammatory cell infiltration(Fig. 4A, Band C). The capillaries were dilated and congested in dermis (Fig. 4A). In the alopecic area, tissue with extensive exfoliated hyperkeratosis covered the epidermis, and all the epidermis and dermis tissues exhibited necrosis and extensive neutrophil infiltration (Fig. 4B). The histopathological scores are presented in table 3. The number of cutaneous lesions between gorals from Changan and Ningshan was not significantly different (p =0.21>0.05). Dead takins, giant pandas, golden monkeys and wild boars had no cutaneous lesions on gross or histological examination in this study.
Parasitologically, mites and eggs were observed in only cutaneous scrapings and cultures from all dead gorals and serows under the microscope. Mites from both gorals and serows presented a globular idiosoma with triangular spikes on the dorsal surface, a wide gnathosoma, short and thick posterior legs and a terminal anus, consistent with S. scabiei morphology (Fig. 4D)