Pregnancy toxemia (PT) is a metabolic disease of ewes and does that occurs in the final weeks of pregnancy. Clinical signs of the condition include a gradual decrease in food intake, depression or inactivity, down and unable to rise, tremors, wobbly, weakness, circling, grinding of the teeth, and if left untreated may result in death of the animal.
The disease is typically seen in animals which carry one large fetus but can also be seen in animals which carry multiple small fetuses. The condition develops due to a reduced ability to consume sufficient energy from their diet to meet the energy demands of the mother and her babies. Ewes/does who are obese or very thin are more at risk of developing this condition. This condition appears to be on the increase, especially in Boer goats that are carrying as many as four fetuses.
Given the value of these animals, ultrasound at 30-70 days of pregnancy is highly recommended to identify those with multiple fetuses. This allows the caretaker to separate those that are more prone to the development of pregnancy toxemia.
Preventing pregnancy toxemia involves three management goals. Adequate nutrition should be provided during the final weeks of pregnancy, there should be ample room for exercise, and control of other conditions that might result in reduced feed intake or increase energy demand, such as parasitism, mastitis or foot-rot.
As the mother’s uterus enlarges towards the end of pregnancy, there is less room for her stomach (rumen) to fill with feed. Therefore, at this time the diet needs to be high in energy and foods such as cereal grain and alfalfa hay are very good sources of energy.
Ewes and does carrying 3-4 fetuses should be offered 1-2 pounds of grain per animal per day during the last month of gestation. The increase in intake of high energy dense foods to 1-2 pounds per day should be accomplished gradually so as not to upset the normal function of the rumen, which may precipitate the onset of pregnancy toxemia.
The most important aspect of successful treatment is early recognition of the clinical signs mentioned above. Once animals become recumbent and refuse to get up, medical treatment is usually unrewarding and a cesarean section (C-section) is recommended to immediately remove the negative energy drain of the fetuses on the mother.
Often by the time this stage has been reached the fetuses may not be viable. If the fetuses are delivered by C–section more than a week before the normal pregnancy duration in sheep and goats (approximately 5 months) is reached, the babies have little chance of survival.
In some instances the mother is more important to the breeding program than the babies and thus the babies may be sacrificed. In other situations, the babies may be more important. Therefore, if you suspect your animal may be developing pregnancy toxemia, you should seek veterinary assistance immediately since early treatment provides for a much better outcome.
This column is provided by the faculty of the OSU Boren Veterinary Medical Teaching Hospital.