Red Skin, Erysipelothrix Infection, St. Anthony's Fire
Erysipelas is a bacterial infection of the outer layers of the chicken's skin. It is a form of cellulitis, except unlike cellulitis, almost all erysipelas is caused by Erysipelothrix rhusiopathiae
or Group A beta haemolytic streptococci (Streptococcus pyogenes
What are the clinical signs of erysipelas
Erysipelas usually occurs abruptly and predominantly affects the skin of the lower limbs of the bird. Affected birds also often have a fever.
- It is bright red, firm and swollen. It may be finely dimpled.
- The affected skin has a very sharp, raised border.
- It may be blistered, and in severe cases may become necrotic.
- Bleeding into the skin may cause purpura.
- Cellulitis does not usually exhibit such marked swelling, but shares other features with erysipelas, such as pain and increased warmth of affected skin.
How chickens become infected with erysipelas
enters the chicken's body through breaks in the skin, such as open wounds and scratches. The organism is able to survive in the soil and decaying organic matter in the environment for long periods of time. The red poultry mite (Dermanyssus gallinae)
, is a potential vector of E. rhusiopathiae
, and can act as reservoir hosts, allowing it to persist on the premises between flocks as a source of infection for the next flock of birds. Infection with E. rhusiopathiae
has also been linked to chickens consuming fish meal.