The histological lesions of Trichophyton mentagrophytes var erinacei infection in dogs

A retrospective study of the histological features of four cases of canine Trichophyton mentagrophytes var erinacei infection is reported. In all four dogs the initial lesions affected the dorsal muzzle and in two dogs the le sions spread to more distant sites on the body. Clinically, the lesions wer e characterized by scaling, crusting and hair loss. Histologically, the mai n lesions were characterized by acanthosis, epidermal, ostial and infundibu lar hyperkeratosis, serocellular crusting, mural folliculitis and furunculo sis. Fungal hyphae were usually sparse and often difficult to see in haemat oxylin and eosin stained sections. When Visible they were seen in the epide rmal, ostial and infundibular scale and, less frequently, within hair shaft s.