Dermatophytosis caused by Trichophyton mentagrophytes var. erinacei in a dog: a case report

Trichophyton mentagrophytes var. erinacei is rarely isolated from dogs with dermatophytosis. It is a zoophilic dermatophyte transmitted by hedgehogs and, in contrast to other dermatophyte species, is characterised by a severe suppurative and inflammatory response known as kerion. A 5-year-old male mongrel dog was referred to the Veterinary Teaching Hospital with a 2-week history of a localised pruritic and suppurative alopecic lesion on the scrotum. Routine blood tests, peripheral blood smears, multiple skin scrapings and bacteriological culture did not reveal any abnormalities. However, Trichophyton mentagrophytes var. erinacei was isolated from a fungal culture. The presence of hedgehogs around the daily walking areas of the dog suggested the possibility of direct or indirect contact of the dog with hedgehogs. Fungicidal treatment was implemented with oral itraconazole (5 mg/kg once daily) and topical application of clotrimazole (twice daily) for a month. The scrotal lesion healed completely and hair grew back within a month. No recurrence occurred during a 4 month follow-up. T. mentagrophytes var. erinacei should be included in the differential diagnosis of suppurative scrotal skin lesions of dogs, which have come into possible contact with hedgehogs.