synonym Mycotic Pneumonia
Various fungi including Aspergillus fumigatus.
Occurrence and Economic Significance
The disease is world-wide in distribution but cases are more frequently diagnosed in tropical countries especially during warm and humid weather.
Severe outbreaks associated with hatchery contamination may result in up to 15% chick mortality during the first two weeks. Decreased growth rate and ascites complex are noted in affected survivors.
Contamination of egg shells with Aspergillus spores results in colonization of the air cell. This is followed by subsequent infection of the respiratory tract of pipping embryos and hatching chicks. Horizontal transmission can occur in the hatchery or during handling and delivery. Chicks older than 48 hours are usually refractory to infection by inhalation of spores.
Morbidity may attain 10% of the flock with corresponding mortality during the first 3–12 days. Affected chicks are disinclined to move and show labored breathing with extension of the head, frequently accompanied by a whistling rale.
Mycotic encephalitis (infection of the brain) results in lateral recumbency, incoordination and coarse muscle tremors.
Numerous 1mm diameter yellow to green nodules are observed in the lungs and air sacs and occasionally in other organs including the brain and eye.
Characteristic lesions are highly suggestive of aspergillosis. Confirmation of the diagnosis requires culture using an appropriate fungal medium (Sabouraud’s dextrose agar). Histological examination of lungs will reveal characteristic hyphae.
Improving nest-box hygiene, increasing the frequency of collection of eggs to four times daily and where possible, substituting plastic nest pads for litter will reduce the prevalence of aspergillosis. Decontamination of eggs by formalin fumigation or application of a phenolic disinfectants is advised, but eggs should not be washed by immersion.
Decontamination of setters, hatchers, and air ducts is recommended including the use of aerosol generators and medicated “candles.” The efficacy of cleaning procedures can be monitored, using an appropriate microbiological detection procedure such as an air sampler or exposed petri-plates.
Fowl cholera is a contagious, bacterial disease that affects domestic and wild birds worldwide. It usually occurs as a septicemia of sudden onset with high morbidity and mortality, but chronic and asymptomatic infections also occur.
Chronic respiratory disease caused by M. gallisepticum and synovitis and airsacculitis due to M. synoviae infection, occur world-wide. These conditions are responsible for extensive losses in broiler operations especially where flocks are exposed to concurrent viral respiratory diseases and environmental stress.
Fowl cholera is the reason for great economic loss of poultry in bangladessh