Fingernail onychomycosis without the affection of toenails is uncommon, as was also the causal agent in this case: Trichophyton equinum (TE) transmitted from a race horse to its breeder. This is the second published case of TE onychomycosis (See http://www.iki.fi/raimos). The cure was complete after the course of oral terbinafine for 2 months.