Gaucher disease, an autosomal recessive lysosomal storage disorder caused by mutations in the β-glucocerebrosidase gene, was recently discovered in sheep on a "Southdown" sheep stud in Victoria, Australia. Clinical signs include neuropathy, thickened leathery skin, and ichthyosis, with lambs unable to stand from birth. Affected lambs were found to be deficient in glucocerebrosidase activity, and mutational analysis found them to be homozygous for the missense mutations c.1142G>A (p.C381Y) and c.1400C>T (p.P467L). In addition, four silent mutations were detected (c.777C>A [p.Y259Y], c1203A>G [p.Q401Q], c.1335T>C [p.I445I], c.1464C>G [p.L488L]). The human equivalent [C342Y] to the C381Y mutation leads to an acute neuronopathic phenotype in patients. Identification of an acute neuronopathic form of Gaucher disease in sheep provides a large animal model that will enable studies of pathology and evaluation of therapies to treat this common lysosomal storage disorder.