A congenital disease of lambs clinically similar to 'inherited cerebellar cortical atrophy' (daft lamb disease).

SUMMARY In the spring of 1973 seven of 22 ewes in a pedigree Border Leicester (BL) flock, all mated to the same BL ram (Double M) produced eight lambs showing clinical signs strongly suggestive of ‘inherited cerebellar cortical atrophy’ (Innes, Rowland & Parry, 1949), the disease which has been better known under its colloquial name, daft lamb disease (DLD). However, histological examination of the CNS from four affected lambs failed to reveal any evidence of cerebellar lesions. A breeding trial carried out on the farm proved the disease to be inherited, most likely as an autosomal recessive trait. Clinical, neuropathological and electro-encephalographic study of lambs born to the original carrier parents over two consecutive years has established that the condition is clinically indistinguishable from DLD, but differs from it by the absence of any specific damage to the cerebellum or other parts of the CNS on one hand, and on the other by the presence of skeletal fragility and a specific progressive myopathy. It is suggested that the clinical syndrome of DLD comprises more than one pathological entity.