Congenital Defects of the Nervous System of Lambs

Abstract

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.

Congenital meningocele with a rare skull defect in a lamb

“…Despite the surprising comment of Kalter 4 that 'some of the defects of the nervous system which were among the commonest in other species were apparently unheard of in sheep', other reports have confirmed that the prevalence of congenital defects affecting the nervous system in lambs is about 1% 5 to 1.5%. 2 Of the 67 lambs with congenital defects of the nervous system observed at necropsy by Dennis, 2 8 lambs (about 12%) had meningocele. Of these, seven meningoceles were situated in the occipital region of the cranium with openings into the cranial cavity with diameters of 1.5 to 1.8 cm.…”

Surgical Treatment of a Canine Intranasal Meningoencephalocele

“…Reports of meningoencephaloceles are uncommon in the veterinary literature 6,12–19 . In 1974, canine meningoencephalocele was first described in a 2‐day‐old puppy 12 .…”

Aprosencephaly with Otocephaly in a Lamb (Ovis aries)

“…In a 3-year necropsy study, 67 of 4417 lambs were affected, a prevalence of 1.5%. 7 Of these 67 cases, 19.4% were solitary central nervous system defects not associated with defects of other organ systems. Hydrocephalus (15 cases) and spina bifida (9 cases) were most common.…”