Aspergillosis In Poultry

 known as 'brooder pneumonia', aspergillosis is a disease of very young chicks. It is a disease of

the respiratory system, and usually occurs when there are poor sanitary practices on the farm. Newly

atched chicks are highly susceptible to infection. Stress of cold, high ammonia, and dusty environments increase incidence and severity of the disease.

Cause

The disease is caused by a fungus called Aspergillus fumigatus. Contaminated poultry litter is usually the source of infection. Chicks become infected during hatching or during the first day or two in the brooder house, hence the name 'brooder pneumonia'.

Spread

Infection occurs by inhalation of spores from contaminated feed or litter. A spore is that form of fungus which is very tough and resistant, and is therefore difficult to destroy. Fungal growth in wet litter produces large numbers of spores. These spores spread as suspended particles in air as wet litter dr ies.

Symptoms

The affected chicks may stop eating and show symptoms of gasping or laboured breathing. They breathe with an open mouth due to obstruction of the airway.

Postmortem Findings

The lungs are the main organ affected. They show small nodules that are hard and yellow . In some cases nodules are only a few, in others there may be hundreds. Nodules are also seen in the trachea and airsac.

Diagnosis

Aspergillosis is usually diagnosed at postmortem examination. Examination of the trachea or a cut lung will show nodules. This forms a basis for the diagnosis.

Treatment

Apart from providing adequate ventilation, there is no treatment for birds that are affected.

Control

I. A thorough cleaning of the brooding premises will eliminate the source of infection for future flocks.

2. Any mouldy feed should be removed, feed containers cleaned, and old litter removed from the house and replaced with new.

3. Drinkers and feeders should be cleaned and disinfected.

4. Since M. gallisepticum is transmitted through eggs, maintaining chicken flocks free of M. gallisepticum is only possible by obtaining replacement flocks that are known to be free of the infection, and rearing them in strict isolation to avoid introduction of the disease.