Fig. 1. A non-specific disease, more exactly a lesion, associated to various causes. In most cases, the condition is accompanied with bacterial osteomyelitis. The figure presents a necrotic focus (N) among the bone marrow of the femoral canal in a 40-day-old broiler chicken with osteomyelitis. H/E, Bar = 40 µm.

Fig. 2. The severe thinning of the cortex in the femoral neck region consequently to rickets, is among the factors predisposing to femoral head fractures and necroses. H/E, Bar = 50 µm.

Fig. 3. Periosteal disruption and fracture in the proximal femoral region in a case of femoral head necrosis. H/E, Bar = 50 µm.

Fig. 4. Abnormal masses of hypertrophic cartilage, protruding into the epiphysis in rickets, that caused femoral head necrosis and fracture at later stage. H/E, Bar = 100 µm.

Fig. 5. Necrosis and hemorrhages among the prehypertrophic cartilage in a case of dyschondroplasia, that initiated femoral head necrosis and fracture in a broiler chicken. H/E, Bar = 25 µm.