Aspergillosis in broilers is a fungal respiratory disease caused mainly by Aspergillus fumigatus and A. flavus. It results in acute or chronic respiratory distress, granulomatous lesions in the lungs and air sacs, and high early‑life mortality. The disease is not contagious between birds; outbreaks arise from environmental contamination, particularly in hatcheries and poorly ventilated broiler houses, and occasionally from contaminated litter or feed.
