In 2009, the Animal Health Service in the Netherlands detected the disease Erysipelas on 14 free-range poultry farms, when a year earlier there were only 10 cases.

 

Erysipelas is caused by the bacterium Erysipelothrix Rhusiopathiae, an environmental bacterium that can infect chickens when they walk outside and are exposed to the external environment. Sick birds show similar symptoms as hens infected with Salmonella Gallinarum.

 

Mortality can be very high and Erysipelas is difficult to treat. When antibiotics are used, the hens are unable to deliver eggs.

 

In practice, the disease is controlled by removing the sick animals as quickly as possible and to vaccinate the remaining animals. There is a good functioning vaccine available. Sometimes, whole flocks are being culled. For farms that have been contaminated, the Dutch Animal Health Service recommends to vaccinate the birds for three consecutive rounds.