Introduction

A complex condition seen in chickens, turkeys and ducks. It may be associated with rapid growth and have a nutritional factor.

Signs

• There are usually no signs unless the condition is severe.
• Swelling and bowing in the region of the knee joints.
• Lameness.

Post-mortem lesions

• Plug of cartilage in proximal end of tibia, distal tibia, and proximal metatarsus, in decreasing order of frequency.
• Microscopically - a mass of avascular cartilage with transitional chondrocytes, small ovoid lacunae and more matrix than normal.

Diagnosis

Gross pathology; mild lesions may require histology to distinguish from other problems. Lixiscope may identify in vivo as early as 2 weeks of age. Differentiate from rickets.

Treatment

None.

Prevention

Genetic selection using the Lixiscope to identify bone phenotype, modifications of calcium and phosphorus ratios, Vitamin D3 supplementation, chloride levels and acid/base balance.