Causes, Control and Prevention Methods of Pregnancy Toxemia in Ewe: A Review

Abstract

Pregnancy toxemia, also known as ovine ketosis, twin-lamb disease or gestational toxemia is a metabolic disease affecting pregnant ewes. The objective of this review is to highlight possible causes and predisposing conditions of pregnancy toxemia in ewe and to indicate successful control and prevention methods of the disease. English articles published from 1983 to date was searched with Google using toxemia, pregnancy, ewe, treatment, prevention, ketosis and diagnosis as key terms. The increased requirement for energy during pregnancy, accompanied by inadequate nutrition to meet metabolic requirement is the underlying cause of the disease. This negative energy balance initiates the onset of excessive lipid metabolism and ketosis, and eventually causes hepatic lipidosis. An excess of ketone bodies can occur in both poor and good conditioned sheep and in fact, excessively fat ewes can be more prone to pregnancy toxemia. Moreover, conditions that interrupt feed intake, such as storms, hauling or other diseases can also induce this metabolic disease. Affected sheep exhibit weakness and depression, usually within the last six weeks of pregnancy. It has seen more often in older ewes and those carrying multiple fetuses. Pregnancy toxemia is almost never observed in replacement ewe-lambs or yearlings lambing for the first time. If untreated, the disease progresses, causing neurological signs and eventually death. Therefore, Understanding the causes, pathogenesis, prevention and treatment of this disease is important in preventing production loss in sheep farming operations