Fungal diseases
Aspergillosis
Aspergillosis is mycotic disease of poultry and all other species of birds caused by a fungus known as Aspergillus fumigatus. Feed or litter contaminated with the fungus particularly in damp environment is responsible when a large number of spores are inhaled by the birds. Immunologically compromised or stressed birds are more susceptible. Aspergillus can penetrate egg shells under ideal conditions and infect the embryo. Such eggs may appear green when candled. Infected embryos may hatch with well developed lesions.
Symptoms and lesions: Young, brooding chicks are more susceptible (hence brooder's pneumonia). The clinical signs seen are dyspnoea, gasping, accelerated breathing, diarrhoea, anorexia, progressive loss of weight and increased thirst. In certain cases, nervous signs also appear.
Small whitish or yellowish nodules and plaques are seen in the lungs and air sacs, cheesy mass deposited in trachea; mycelial growth may be apparent as fuzzy green material on the air sacs.
Diagnosis: Clinical picture and PM lesions are indicative of the disease. Microscopic examination of crushed nodules from lungs and air sacs on glass slides would demonstrate fungal hyphae of A. fumigatus as a confirmation.
Prevention and control: Aspergillus is a common contaminant of environment. Healthy chicks, balanced nutrition, good management with dry and good quality litter along with necessary sanitary measures would keep the infection away from the poultry.