Differential diagnosis
- Avian Encephalomyelitis - Newcastle disease
- Chronic coccidiosis - Infectious bronchitis
- Infectious laryngotracheitis - Avian salmonellosis
Causative agent
- Aspergillus fumigatus, A. flavus, A. niger
1. History taking
- Take moldy feed and/or raising moldy environment
- A mass outbreak of the disease in a flock
- High morbidity and mortality in baby chicks, but
low morbidity and mortality in young and adult
birds
- Die within 1-2 days in acute, usually be chronic
case
2. Clinical examination
- Dyspnea, gasping, accelerated breathing and loss
of appetite
- Stunting of growth, lethargy, cyanosis, nervous
symptoms, ophthalmitis, swelling of eye ball and
lacrymation in rare cases
3. Necropsy
- Yellowish white caseous nodules (plaques) or
green nodules in the lungs or air sacs, occasionally
in the brain tissue or bursa of Fabricius
- Thickening and cloudy of air sacs
- Hyphae and spores are visible in the air passage
of the lung or air sac or the abdominal cavity
|
4. Histopathological observation
- Periodic acid schiff (PAS) stain reveals granulomas
with a central area of necrosis containing
heterophils and mycelia, surrounded by
macrophages, giant cells, lymphocytes and some
fibrous tissue
- Purulent meningo-encephalitis may be observed
5. Direct microscopic examination
- Preparation of wet mounts in 10 - 20 % KOH,
examine for presence of hyphae, typical fruiting
heads and conidia within the infected tissues
6. Fungi isolation
Specimens : affected tissues
- Culture on sabouraud dextrose agar incubated at
25°C and 37°C for 2-3 days, examine for colonies
and identify microscopic morphology
Control
- Good hygiene and sanitation
- Avoidance of oldy litter or fee
- Frequent cleaning of feed troughs and watering
place
- Distruction of affected birds and rigorous cleaning
and disinfection of environment after outbreak
(spray the building, the air and the litter with
enilconazole solution, 1% copper sulfate or 0.05%
aqueous iodine solution, ruse 1:2000 copper sulfate
or 0.05% aqueous iodine solution in drinking
water) |
| Species |
Colony |
Conidial
head |
Conidiophore
length |
Vesicle |
No. of row of
sterigmata |
Conidia |
|
| A.fumigatus |
blue green to gray green flat, velvety to sligtly floccose or folded
|
compactly
columnar |
short, smooth colorless to light green |
flask-shaped 20-30 μm in diameter |
single series, cover the upper one half of the vesicle |
green globose and echinulate 2.5-3.5 μm in diameter |
| A.flavus |
yellow green to dark green to dark green flat, sometime furrowed, wrinkled |
radiate |
long,thick
walled coarsely roughened colorless |
globose to subglobose 25-65 μm in diameter |
1-2 seies, on the entire surface of vesicle |
yellow brown or yellow orange globose to subglobose and echinulate 3.5-4.5 μm in diameter
|
| A.niger |
Yellow to black granular surface |
brown to black and radiate |
long, thick, smooth hyaline or light brown |
globose 45-100 μm indiamter |
2 series, on the entire of vesicle |
black globose and echinulate 5.5-8.0 μm in diameter |
|
