Sinonasal tumor in 3 dogs after successful topical treatment for frontal sinus aspergillosis

Three dogs diagnosed with aspergillosis developed sinonasal tumors several months after successful treatment with topical clotrimazole solution. Chronic rhinosinusitis was also detected in all cases prior to diagnosis of sinonasal tumors. The inflammatory response to Aspergillus, clotrimazole treatment, and chronic inflammation after treatment are discussed as possible neoplastic promoting factors.