July 15, 2011

In the Spotlight: Recent Disease Investigation from USGS National Wildlife Health Center

From the Latest USGS National Wildlife Health Center Quarterly Wildlife Mortality Report - January 2011 to March 2011

Suspected mycotoxicosis in Canada geese (Delaware)

Sick and dying Canada geese at a private refuge that included both resident and migratory birds were first reported in early January 2011. The area consisted of a 5 acre partially-aerated pond and surrounding fields with standing corn where geese had been observed feeding. Supplemental whole corn was also provided mainly for mallards at the site and was discontinued shortly after the onset of the die-off. Only Canada geese appeared to be involved.

Mortality began slowly and quickly escalated over the course of a week. Mortality continued for approximately four weeks and resulted in 1247 dead geese. Clinical signs were vague consisting mostly of depression and lack of flight response; many were simply found dead. Other birds were seemingly unaffected.

Examination of carcasses from early in the event did not reveal any significant lesions while those collected during peak mortality had evidence of kidney and liver damage. Birds collected late in the event also had evidence of mild aspergillosis. Grain samples collected from the geese as well as from standing corn tested strongly positive for fumonisin B1 toxin by two independent labs. High levels of this toxin are known to cause liver changes in domestic poultry but its effects on waterfowl have not been previously studied.

Source: USGS National Wildlife Health Center, Quarterly Mortality Reports

More Resources

National Wildlife Health Center
University of Florida - Institute of Food and Agricultural Sciences (IFAS) Extension