A two-year-old male castrated Rottweiler mix breed dog presented to the Cornell University Hospital for Animals’ (CUHA) Internal Medicine Service on August 9, 2012 for further evaluation of episodes of unilateral epistaxis of approximate one month duration. The referring veterinarian (rDVM) performed an initial complete blood count and chemistry panel, which revealed an eosinophilia. Skull radiographs, also performed by the rDVM, showed an increased opacity in the right nasal cavity. The dog was placed on various antibiotics, which initially resolved the epistaxis, but resumed as a chronic serous nasal discharge. Other pertinent history included a propensity to dig and contact with a porcupine, which embedded quills into his face and foot. During his initial visit to the CUHA a computed tomography scan of the head was performed which confirmed a soft tissue opacity with turbinate lysis in the right nasal cavity and soft tissue proliferation in the right frontal sinus. Rhinoscopy found no visual abnormalities in the nasal cavity. His right frontal sinus was trephined and a white amorphous mass was visualized and later confirmed to be an Aspergillosis infection on hisopathology. He returned a few weeks later for treatment of Aspergillosis with a topical infusion of 1% Clotrimazole solution and cream into both frontal sinuses. This paper discusses nasal disease in dogs and specifically the diagnosis and treatment of canine nasal aspergillosis.