Pregnancy Toxaemia in Sheep: A Metabolic Emergency

Pregnancy toxaemia (twin lamb disease) is a metabolic condition affecting ewes in late pregnancy, particularly those carrying multiple foetuses. It causes serious suffering and high mortality without prompt intervention.

Key Facts

Pregnancy toxaemia results from a negative energy balance in late pregnancy when foetal glucose demands exceed the ewe's intake and metabolic capacity
Ewes carrying twins or triplets are at highest risk, particularly if body condition is poor or nutrition is inadequate in late gestation
Clinical signs include separation from the flock, depression, star-gazing, blindness, recumbency, and death within days if untreated
The condition is most common in the last 4-6 weeks of pregnancy when foetal growth is most rapid
Blood ketone levels and glucose measurements are used to diagnose and monitor the condition
Treatment involves oral or intravenous glucose supplementation, propylene glycol drenching, and supportive care
Prevention is achieved through careful body condition scoring and targeted nutritional management in late pregnancy

Welfare Considerations

Pregnancy toxaemia causes rapidly progressive neurological deterioration: affected ewes develop confusion, apparent blindness, and loss of coordination before becoming recumbent and unable to rise. The condition is acutely distressing and, without intervention, fatal within 3-5 days. Ewes experiencing prolonged recumbency develop secondary pressure sores and muscle damage. The welfare of the unborn foetuses is also compromised — hypoglycaemia in the ewe starves developing lambs. Even with treatment, ewes in advanced stages have a poor prognosis. Prevention through proper body condition scoring and targeted late-pregnancy nutrition is far more effective than treatment, yet many affected farms have inadequate nutritional monitoring programmes.

What You Can Do

Implement body condition scoring at weaning, mid-pregnancy, and pre-lambing on all sheep farms
Provide targeted supplementary feeding to thin ewes or those carrying multiple foetuses in the final 6 weeks of pregnancy
Monitor ewes daily in late pregnancy — early identification of separated or dull animals enables timely treatment
Keep oral propylene glycol and drenching equipment readily available during lambing season
Work with a vet or sheep consultant to develop a pregnancy nutrition plan appropriate for your flock
Support sheep welfare organisations developing practical guides for nutritional management in late pregnancy