Skeletal abnormality of sheep: clinical radiological and pathological account of occurrence of dwarf lambs.

Details are given of the clinical, radiological and pathological appearance of dwarf lambs. Twenty-seven of 110 lambs born were affected, occurring as singletons, twins or one of a pair of twins. All affected lambs were dead within a few minutes of birth. They were short and plump with a domed head and shortened nose, short paddle-like limbs, a narrow thorax and swollen abdomen. The defect involved chondrocyte dysplasia, producing defective endochondral ossification and the presence of abnormal cartilage in the respiratory tract. No specific genetic or environmental cause was identified.