Dermatophytosis in a Steller sea lion (Eumetopias jubatus)

Serious dermatophytosis caused by Trichophyton mentagrophytes was found in a Steller sea lion (Eumetopias jubatus) at Yomiuri Land Marine Aquarium in Tokyo. The external clinical signs were extensive depilation and hyperkeratosis, as well as redness and depigmentation of the skin. Histopathological findings of the skin revealed PAS positive fungal hyphae with septa in the corneum layer of the epidermis. Further microscopic examination suggested that this lesion of the skin was typical chronic dermatophytosis. Based on morphological and growth characteristics, the isolate was identified as Trichophyton mentagrophytes. It was thought that the infection was due to some factors including species and individual specific and environmental factors and so on.