Wildlife officials with the DNR are taking steps to prevent the further spread of avian cholera after the disease was detected at a wetland area in northwest Iowa.
DNR Wildlife officials report that avian cholera has been detected at Rush Lake in southwest Palo Alto County. Avian cholera is a contagious disease that can be harmful to domestic poultry and migratory waterfowl, but is not considered a high risk for humans. Standard disease protection procedures should be used when working with diseased animals, including wearing rubber gloves and washing skin thoroughly.
Since April 9th, a total of 213 ducks and geese, consisting of 16 species have been removed from Rush Lake in southwest Palo Alto County. Analysis of a sample of these by the National Wildlife Disease Center (NWDC) in Madison, WI, indicated that avian cholera was the cause of death. Since April 9th, DNR staff has surveyed Rush Lake and surrounding wetlands on a bi-weekly basis and has followed NWDC protocol regarding the retrieval and disposal of dead birds. This, combined with lowering water levels to make Rush Lake less attractive to waterfowl appears to be working, as the number of dead birds found has decreased significantly. DNR staff will continue to monitor Rush Lake and surrounding areas until no newly deceased birds are found.
Waterfowl most frequently become infected with avian cholera when feeding in waters contaminated with high numbers of the disease carrying bacterium or through direct contact with infected birds. The bacterium often enters the upper respiratory tract, but infection can also be through eye membranes or skin abrasions. Once infected, death can occur in as few as 6 to 48 hours. Field signs include lethargic birds swimming in circles or in stationary positions with their heads held over their backs, and dead birds that otherwise appear to be in good physiological condition.
Iowa Secretary of Agriculture Bill Northey told the Pilot-Tribune that there have been no reports of the disease spreading to commerical poultry operations in the area.