Canine Dermatophytosis Caused by Trichophyton Rubrum: Case Report

A 4-year-old female Shih Tzu dog presented with circular, crusted, and non-pruritic alopecia lesions on its head. Despite normal routine blood tests, skin scrapes, and bacteriological cultures, Trichophyton rubrum, an anthropophilic dermatophyte typically infecting humans, was isolated from a fungal culture. The dog's indoor living conditions likely facilitated transmission from humans. Treatment with a ketoconazole and chlorhexidine-based shampoo and oral Itraconazole at 10 mg/kg daily for 28 days resulted in complete healing and hair regrowth within a month, with no recurrence over a 4-month follow-up period. The study suggests that T. rubrum should be considered when diagnosing crusted skin lesions in dogs.