Causes: Fungal infection caused by Aspergillus fumigatus, A. flavus and A. niger.
Effects: High mortality, respiratory distress, central nervous dysfunction, sleepiness, inappetance and emaciation. Conjunctivitis and cloudy eyes can be seen.
Detailed causes:
Aspergillosis is mainly seen in young birds as an acute disease. Chronic disease occurs in adults. The fungi Aspergillus fumigatus, A. flavus and A. niger are responsible. It spreads by the aerosol spread of spores, which are common in the hatchery, and less commonly by contaminated dust and litter in the house.
Clinical signs:
Signs include high mortality, respiratory distress (dyspnoea and gasping), central nervous dysfunction (tremors, ataxia, and torticollis) somnolence (sleepy), inappetance, and emaciation (very thin), conjunctivitis and cloudy eyes can be seen.
Postmortem lesions
Yellowish-green or whitish, caseous (cheesy) nodules and/or green, fur-like down in mouth, palate, lungs, trachea, syrinx, viscera, air sacs, brain and eyes may be seen.
Diagnosis:
Fungus can be identified microscopically (20% KOH stain) from culture or special stain of tissues (hyphae, mycelia, conidophores). Isolation of culture in 48 hours on Sabouraud dextrose agar is diagnostic. Stain colony with lactophenol cotton blue to see conidophores. It is similar to colibacillosis, MD, and lymphoid leukosis. Nodules in the lungs and fungal fur-like down in the air sacs are diagnostic.
Treatment and control:
Prevention
Hatchery sanitation includes regular fumigation of eggs, machines and air ducts and regular (monthly) plating of hatchery with media to examine for the presence of fungi. Use clean dry litter and dry cups of nipples to reduce water spills. Quality of the feed is important. An aerosol of thiabenidazole or Clinafarm® pellets can be placed in the hatchery to kill fungus. Formalin fumigation is an effective method to kill Aspergillus in the environment (not in the chicken). This is not allowed in most of the USA.
TreatmentQuaternary ammonium, chlorine, and/or copper sulphate can be added to the water to help reduce the spread of the organism and reduce clinical signs. However, taking preventative measures is more effective.
