Observations on the pathology of bent leg of lambs in South-Western Queensland.

This paper presents the first radiological and pathological description of bent leg, a disease of lambs occurring in the mulga country of south-western Queensland and thought to be caused by plants of the genus Trachymene. In the 5 field cases studied, the deformed limbs were characterised by abnormal diaphyseal curvatures and altered angulation of articular surfaces. There was both radiological and pathological evidence of irregular retardation of growth of epiphyseal plates. It was suggested that ingestion of toxic plant by the ewe interferes with normal endochondral ossification in the foetus. It was further suggested that more severely affected lambs probably occur but do not survive until marking.