What condition does "asper" refer to in birds?

Asper refers specifically to a respiratory infection in birds known as aspergillosis, which is caused by the fungus Aspergillus. This condition leads to inflammation in the respiratory tract and can have serious implications for a bird's health. The infection typically arises when birds are exposed to spores of the fungus, often found in decaying organic matter or contaminated environments.

The condition can manifest as difficulty breathing, lethargy, and decreased appetite, making it critical for bird keepers, including falconers, to recognize the signs early and seek veterinary assistance. Understanding aspergillosis is essential for those involved in falconry, as it emphasizes the importance of proper housing, hygiene, and environmental management to prevent fungal infections in raptors and other birds of prey.