Twin Lamb Disease (Pregnancy Toxaemia) and Ewe Welfare

Pregnancy toxaemia in late-pregnant ewes carrying twins or triplets is a serious welfare condition caused by inadequate energy supply relative to foetal demands.

Key Facts

Twin lamb disease is caused by negative energy balance in the final 6 weeks of pregnancy when twin or triplet foetal energy demands peak
Affected ewes become dull and unsteady, then recumbent and eventually comatose without treatment
Risk is highest in thin ewes (BCS below 2.5) carrying multiples — prevention through body condition management in pregnancy is the primary welfare strategy
Treatment with propylene glycol, glucose and supportive care is effective if initiated early but has poor outcomes in recumbent ewes

Welfare Considerations

Pregnancy toxaemia causes rapidly progressive welfare deterioration from dullness to recumbency and death over 2-5 days without treatment. The welfare impact of the terminal phase — comatose ewes unable to protect or care for their lambs, with the prospect of intrapartum death of both ewe and foetuses — is severe. Prevention through BCS monitoring in pregnancy and appropriate late-pregnancy nutrition eliminates most cases. Scanning to identify twin and triplet-bearing ewes enables targeted nutritional management of highest-risk individuals.

What You Can Do

Pregnancy scan all ewes to identify twin and triplet bearers for enhanced late-pregnancy nutrition
Monitor ewe BCS monthly through pregnancy — target 3.0-3.5 at scanning, not less than 2.5 at lambing
Increase concentrates gradually from 6 weeks pre-lambing in twin and triplet-bearing ewes to meet foetal energy demands
Begin oral propylene glycol treatment immediately in any late-pregnant ewe showing dullness or unsteadiness