Perinatal lamb mortality: Epidemiological and anatomopathological findings in Northeastern, Algeria

Perinatal lamb affections are an essential entity that affects sheep flocks, especially when it has a fatal evolution. This study aims to identify the risk factors implied in perinatal lamb mortalities, describe the anatomopathological and histopathological characteristics of the viscera (lungs, livers, and kidneys) retrieved from twenty lamb corpses and the provided monitoring practices during the perinatal period. The statistical analysis demonstrated that the main factor implied in these mortalities was the hygiene of soil and livestock buildings (P ≤ 0.05). Trachea inspection demonstrated the presence of foamy fluid (n=9/20) and amniotic fluid (n=4/20), grossly bronchopneumonia (n=12/20), interstitial pneumonia (n=4/20) and neonatal atelectasis (n=4/20). The livers showed acute hepatitis (n=15/20). Moreover, kidneys showed acute glomerulonephritis (membranoproliferative and glomerulosclerosis) (n=13/20), associated with hydronephrosis in six cases and epithelial nephritis in two cases (n=2/20) and hydronephrosis in two stillbirth cases (n=2/20). The principal histologic lesions observed on the lungs, livers, and kidneys were acute hyperemia, hemorrhage, inflammatory cell infiltration (neutrophils), and parenchyma destruction. In stillbirths, the presence of bright yellow materials (meconium fragments) in the lung parenchyma recognizes the involvement of meconium aspiration syndrome. The correlation between anatomopathological and histopathological results was essential in understanding the evolution of these affections and highlighting the conditions that led to the death. Furthermore, this study revealed a lack of preventive sanitary protocols, assisted lambing, and appropriate care strategies for lambs during their first days of life which contributed to the fatal evolution of these perinatal affections.