Antitrochanteric and acetabular lesions in adult male breeding turkeys

In order to elucidate the pathogenesis of antitrochanteric degeneration in turkeys, histopathological studies were conducted on the os coxae of 25 adult male breeding birds. Acetabular lesions were also observed and described. Lesions were detected, by light microscopy, in 90% of antitrochanters examined and 75% of lesions were considered to be progressive. This illustrates the high incidence of antitrochanteric degeneration in adult male turkeys. The fundamental lesion leading to gross antitrochanteric disruption, is thought to be cleft formation within middle and deep uncalcified cartilage and cartilage at this site is probably vulnerable because of its relative acellularity. Clefts are interpreted as fatigue failure, probably in shear, of collagen fibrillar structure. Vascular abnormalities were also observed and the vulnerability of blood vessels within deformable cartilage canals was demonstrated. The presence of chondro-osseous fractures in. some antitrochanters supports the concept that lesions have a traumatic aetiology.