Confirmed case of feline mycetoma due to Microsporum canis.

The first case of feline true mycetoma because of a dermatophyte has been reported in this manuscript, although pseudomycetoma has been described in dogs and cats. The patient was a 9-year-old castrated male Persian cat weighing 4.2 kg with subcutaneous nodules on the dorsal trunk. Physical examination revealed two subcutaneous nodules (2.5 x 5.0 cm and 3.5 x 5.0 cm in size) that drained purulent exudates with cement-like substances containing yellowish granules. The impression smear of the yellowish granules demonstrated by PAS staining that they were masses of fungal septated hyphae (3-4 mum of width). From the nodular inflammation with fibrosis, fistulae draining from deep tissue and many grains containing abundant hyphal filaments, the case was diagnosed as mycetoma, complying with the definitive criteria of mycetoma. The etiologic fungus was molecularly as well as morphologically identified as Microsporum canis.