Aspergillosis is the most frequently occurring fungal infection in birds.
All species are susceptible.
It may be contracted as the result of inhalation of fungal spores or oral ingestion, especially if birds are fed moldy food or housed on contaminated bedding. Immunocompromised and malnourished birds are most susceptible to the disease. Diagnosis of aspergillosis can be difficult. A tentative diagnosis may be made of the basis of physical findings, a history of environmental conditions suitable for fungal growth, and recent stress. As the disease becomes more chronic, a monocytosis, lymphopenia, and non-regenerative anemia develop.