Congenital defects of the nervous system of lambs.

Sixty-seven defects of the nervous system of lambs were examined during a 3-year investigation. Thirteen (19.4 percent) were single defects, and 54 (80.6 percent) were associated with defects of other body systems. Twice as many male lambs as females were affected. The various defects were: hydrocephalus 15, spina bifida 9, meningocoele 8, perosomus elumbis 8, cyclopia 6, cerebellar agenesis 3, aprosopia 3, cranium bifidum 3, anencephaly 2, cerebellar fusion 2, meningo-encephalocoele 2, congenital ataxia 2, micrencephaly 2, cerebellar hypoplasia 1, and acrania 1. A number of lambs had more than 1 defect of the nervous system. Congenital defects of the nervous system were found in 1.5 percent of the 4,417 lambs autopsied.