Introduction

A complex condition seen in chickens and turkeys. Morbidity is 1-20% and mortality is low. Factors involved may include genetics, nutrition, environment and high growth rate.

Signs

• Lameness.
• Distortion at hock.
• Valgus/varus.
• Various angulations of leg.
• Gastrocnemius tendon may slip.

Post-mortem lesions

• Linear twisting of growth of long bones.
• Changed angulation of tibial condyles; intertarsal angulation up to 10% is physiological, greater than 20% is abnormal.

Diagnosis

Symptoms, lesions. Differentiate from perosis, arthritis and synovitis.

Treatment

None.

Prevention

Selection for good conformation in primary breeding. Adoption of optimal nutrition and growth patterns for the economic objectives of the production system.