A vertically transmitted cystic renal dysplasia of lambs

A new form of bilateral renal dysplasia in lambs appeared in a commercial sheep flock in 1982. The nature of the problem, the field investigations and the laboratory examinations carried out over three lambing seasons are described. It was concluded that the condition was vertically transmitted and genetic in origin. During the two years that accurate records were kept approximately 30 per cent of the suspected ram's progeny died with lesions of renal dysplasia. The condition recurred during a breeding trial in progeny from one of the two commercial rams originally used on the farm. An autosomal dominant mode of inheritance is suggested. The incidence illustrates the importance of keeping breeding records, especially when several rams are maintained in a flock, and the value of examining a large number of lambs post mortem.