A Case of Generalized Canine Dermatophytosis

Abstract

Crusts were seen on the upper eyelid of a 14-year-old Yorkshire terrier, which had been treated with cyclosporine ophthalmic ointment and difluprednate emulsion eye drops for approximately 10 months due to serious keratitis sicca. Although oral administration of antibiotics and local treatment were applied, no improvement was observed. Subsequently, symptoms such as crust formation, erythema, and hair loss developed, spreading as far as the neck, anterior chest and forelegs. While no external parasites were detected by a skin curettage test, fungi were found in a culture test. Furthermore, skin biopsy revealed that fungal infection inside the hair follicles had reached as deep as the lower dermis, and the causal fungus appeared to be filamentous. Therefore, oral and external medicines including terbinafine hydrochloride were given for approximately one month, which resulted in the disappearance of the crust and erythema, along with significant growth of new hair approximately two months later. The skin condition is getting better, and the dog is also fine.