Abstract
Feline upper respiratory tract infection due to Aspergillus spp. is considered an emerging disease, with the number of reported cases continuing to rise. In this study, we report the first case of feline sinonasal aspergillosis caused by Aspergillus fischeri in Japan. The patient presented after 2 months of progressive facial deformity around the nose and nasal discharge. The isolate from this case was susceptible to itraconazole (ITZ), voriconazole and micafungin, but was resistant to amphotericine B. However, the infected cat died approximately 1 month after referral, despite treatment for 12 days ITZ administered orally at 10 mg/kg.