Pregnancy Toxaemia in Small Ruminants

Abstract

Pregnancy toxaemia (PT) is a condition occurring in ewes and does during the last month of gestation. It is characterized by anorexia, ruminal atony, depression, and reluctance to stand or walk. This condition carries a poor prognosis with a reported case fatality rate above 80% even when a caesarean section is performed or after the induction of kidding. Metabolically, PT leads to ketonemia, metabolic acidosis, hypokalaemia and hypo, normo or hyperglycaemia. This condition is caused by negative energy balance resulting from increased energy demands for rapid foetal growth during late gestation. In pregnant ewes low quality roughage is a particular risk because not enough can be consumed to meet requirements when the rumen volume is reduced by the presence of an enlarged uterus in the abdomen. PT occurs commonly in dairy goats especially in specific breeds, like Saanen and Alpine, which are genetically more prone to become pregnant with multiple foetuses. Goats are considered to be tropical/sub-tropical animals and their body fat stores are laid down in intraabdominal fat rather than in the subcutaneous tissues as occurs in cows and ewes. Because of high mortality rate characteristic of PT, the strategy to deal with this condition should be based on prevention.