Leg injuries commonly found in birds raised for meat
Hock burns are lesions found on the hock joints of chickens and other birds raised on broiler farms. They are considered a form of contact dermatitis.[1] These marks occur when the ammonia from the waste of other birds burns through the skin of the leg, leaving a brown ulcer mark.[2] The condition has been found to be a source of pain for birds, can cause mobility issues, and may increase the risk of bacterial diseases.[3][4][5] In severe cases, hock burns can cause visible scabs to form.[6]
Higher rates of hock burns are often used by observers as an indicator of what they see as worse animal welfare conditions.[5] This is in part due to how they occur more often in overcrowded conditions and in birds genetically modified to grow fast. Although the meat is still safe to eat, many processors now remove these marks as they discourage customers.[2]