Avian Medicine Q&A 14

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When opening the air cell of a suspected dead Canada goose egg, you encounter the situation shown above.

Question	Answer		Article
What is the aetiological agent that produces the pathology seen in this egg?	The figure shows a fungal infection growing in the air cell of the membrane. The most common aetiological agents producing such growth are Aspergillus sp., typically A. fumigatus but occasionally A. flavus.		Link to Article
In addition to the lesion pictured, what are the other signs of this particular causative agent found in embryos or newly hatched birds?	Embryos may die before hatching or be weak and dyspnoeic after hatching. Occasionally, nervous system problems or diarrhoea are found in birds that survive to hatch. Post-mortem findings include bronchial or tracheal plugs, air cell plaques or small yellow nodules in the lungs.		Link to Article
What is required for positive diagnosis?	Cultures of lesions on the air cell membrane, lungs, air sacs or air passages are collected for positive identification.		Link to Article
What are recommended treatments and preventive measures for this problem?	There is currently no recommended treatment for eggs infected with aspergillosis; efforts should be concentrated on prevention. Aspergillosis can be a serious problem in forced-air incubators. Always clean and fumigate incubators and hatchers between batches of eggs and operate an ‘all in, all out’ policy. Eggs should be examined – weighed; candled; examined for cracks – at regular intervals. Dead eggs should be removed at once as contamination of viable eggs by dead Aspergillus-infected eggs can occur. Eggs from damp or wet nests should not be incubated. UV sterilization of eggs may be used prior to incubation, as may sanitizing dips or washes.		Link to Article