Cyclic dermatitis associated with Fusarium sp infection in pinnipeds

Abstract

Dermatitis associated with Fusarium sp infection developed in 3 California sea lions (Zalophus californianus) and 3 gray seals (Halichoerus grypus) at the National Zoological Park in Washington DC. The lesions were papular or nodular and were distributed mainly on the face, trunk, and flippers. One sea lion died 6 weeks after extensive cutaneous involvement. The lesions regressed after 1 mild exacerabtion in the other 2 sea lions. In the gray seals, the skin condition appeared to worsen during the summer and to regress during the winter, despite oral and topical treatment with miconazole and thiabendazole. Fusarium sp was repeatedly isolated from biopsy specimens of lesions. Hyperplasia of epidermal and follicular epithelium was associated with acute and chronic inflammation and fungal hyphae. The species of the fungus in 1 of the gray seals was determined to be F solani, a type occasionally associated with keratitis and opportunistic infections in human beings. Initial excessive chlorination and high fluctuating pool temperatures attributed to a faulty water treatment system were considered as factors in promoting fungal growth.