Aspergillosis is an opportunistic infectious disease caused by a number of aspergillus spp, especially A. fumigatus. It is found worldwide, in human being and almost all domestic animals and birds as well as in many wild species. It is primarily a respiratory infection that may become generalized; however tissue predilection varies among species. The most common forms are pulmonary infection in poultry and other birds, mycotic abortion in cattle, guttural pouch mycosis in horses, and infections of nasal and paranasal tissues of dogs. Pulmonary and intestinal forms have been described in domestic cats. A 5 years old mixed mesaticephalic native dog (sarabian fight dog) presented with a history of persistent nasal sanguineous discharge, anorexia, depression, weight loss during past 1 year and rapidly getting breathless while practice, with multiple non successful treatments. Clinical assessments showed only mucopurulent and sanguineous nasal discharge and pulmonary wheezes. Minimum data base was collected and there was no platelet deficiency, urine and liver tested and all were normal except Mild neurophilia and monocytosis. Radiographic evaluation showed soft tissue density in nasal cavity (figure-1) and severe lung involvement with cotton ball like densities. In the same time direct nasal samples collected and at the first glance hyphae and some conidia were seen. Culture results showed aspergillus fumigatus infection. Tracheal wash samples also showed the same results that mean pulmonary fungal infection. Treatment started promptly with oral ketoconazole (10mg/kg bid for 3 months) with broad spectrum antibiotics, vit K, and nasal lavage with diluted chlorhexidine 4 times daily. Obvious recovery achieved after 50 days with 12 kg weight gain, treatment didn't stop, and continued with amphotricin B (3 times per week 0.15-1 mg/kg) for 60 days, but ketoconazole was continued. At the end, the dog was successfully treated (no recurrence up to now, 7 months after stopping the treatment) and final weight reached 62 kg. No nasal discharge and no breathlessness during practice were seen.