Introduction

This is a condition causing severe lameness in roaster type meat chickens and more rarely in turkeys. Reoviral or staphylococcal arthritis or tenosynovitis may predispose but many cases have no evidence of an inflammatory response. Broiler chickens have an avascular area of tendon just above the hock that is the usual site of rupture. Ruptures of ligaments and joints are also occasionally seen.

Signs

• Severe lameness.
• The bird may have the hock dropped to the floor. If there is a greenish tinge to the area of swelling it occurred a few days previously.

Post-mortem lesions

• The fresh lesion contains a haematoma with the end of the ruptured tendon within or adjacent to it.

Diagnosis

Signs and lesions are obvious. Histology may be helpful in determining if there is an underlying inflammatory process.

Treatment

None. Affected birds should be culled humanely as soon as they are identified.

Prevention

Establishment of a steady growth profile. Avoidance of physical stresses on the musculo-skeletal system through careful handling as well as careful design and layout of equipment.